Dictionary of computer

antages. First, they can transmit more data because they have a great bandwidth. They're also thinner, lighter and less susceptible than metal cables to interference. And they can transmit data digitally rather than analogically. FirewallA firewall is a system that secures a network, shielding it from access by unauthorized users. Firewalls can be implemented in software, hardware or a combination of both. In addition to preventing unrestricted access into a network, a firewall can also restrict data from flowing out of a network. FireWire*FireWire is a high-speed serial bus system. It is the IEEE1394 standard for I/O technology that connects multimedia and storage peripherals to a PC. FireWire (Apple), 1394* (Linux) and iLink* (Sony) are different names for products that perform the same function. FireWire can provide a bandwidth of about 400 Mbps. Floating PointCalculations that use an exponent with numbers to indicate the location of the decimal "floating" point is known as Floating Point Arithmetic. These numbers have two parts: a mantissa and an exponent. The mantissa designates the digits in the number and the exponent designates the position of the decimal point. FrequencyUsually measured in Hertz (Hz), frequency is the rate at which an electrical current alternates. Sound waves travel in cycles with upper and lower frequency limits. GPRS (General Packet Radio Service)GPRS is a standard for wireless communications that allows packets of data, such as e-mail and Web content, to travel across a wireless telephone network and to the Internet. GPRS is often referred to as "2.5G" technology (in comparison to first- generation (1G) wireless technology which is used for analog cell phones, and second-generation (2G) wireless technology which is used for digital cell phones). In addition to the GPRS cell phone, laptops can be enabled by adding a GPRS adapter to connect to the Internet. GPS (Global Positioning System)GPS is the satellite-based positioning technology that allows a GPS receiver to identify its location anywhere on Earth. GPS receivers can be found as handheld devices, installed in automobiles for navigational aids, and as modules that attach to Personal Data Assistants (PDAs), such as a PalmPilot*. GSM (Global System for Mobile Communications)GSM is a world standard for digital cellular communications using narrowband Time Division Multiple Access (TDMA) for voice and Short Messaging Service (SMS). With 65% of the world's cellular subscriptions on GSM technology, this currently represents the most commonly used cellular technology worldwide. (Source: Gartner Dataquest - Top 20 Mobile Network Operators Worldwide, 2001) Game EngineA game engine is the program that runs all the components that comprise a game, including graphics, audio, collision detection, physics, and artificial intelligence. GatewaySee Wireless gateway. HTML (HyperText Markup Language)The lingua franca (common language) for creating documents on the World Wide Web, HyperText Markup Language (HTML) defines the structure and layout of a Web document by using a variety of tags and attributes (a field or characteristic). HZ (Hertz)Hz is an abbreviation for the international unit for measuring frequency, equivalent to the older unit of cycles per second. One megahertz (MHz) is one million hertz. One gigahertz (GHz) is one billion hertz. The standard US electrical power frequency is 60 Hz. The AM broadcast radio frequency band is 535 to 1605 kHz and the FM broadcast radio frequency band is 88 to 108 MHz. Wireless 802.11b LANs operate at 2.4 GHz. Hard DriveMost computers can read and write data to either a hard or floppy disk. The mechanism that reads and writes to hard disk is called a hard drive. Hard disks hold more data and are faster than floppy disks. In addition, hard drives and associated hard disks are generally components within computers; whereas, floppy disk are removable and portable. High-speed Cable InternetHigh-speed cable Internet is a broadband technology from cable service operators (also known as multi-service operators - MSOs). This technology enables high-speed Internet access to the home over the standard television cable connection. Users can experience data transmission rates from a few hundred kbps to up to 30 Mbps, however, bandwidth significantly varies on a cable network since it is a shared medium. High-speed cable Internet is an open network, offering little security to users who connect directly to the cable connection without a cable/DSL firewall/router device. HotspotA hotspot is a public location such as an airport, shopping mall or conference center that has readily accessible wireless networks, usually 802.11b or 802.11a. HubA hub is a network device that connects multiple computers on a LAN so they can communicate with one another, the rest of the network, and the Internet. All users connected to a hub share the available network bandwidth (unlike a switch, which provides full bandwidth to each computer). Hufmann EncodingHufmann encoding is a compression algorithm that replaces frequently occurring characters and data strings with shorter codes. Each piece of information is read twice, the first time to determine the frequency with which each data character appears in the text and the second time to accomplish the actual encoding process. Hyper-Pipelined TechnologyPart of the Pentium® 4 processor's Intel® NetBurst® micro-architecture. Hyper-pipelined technology doubles the pipeline depth of the Pentium® III processor's P6 micro-architecture, increasing the branch prediction and recovery pipeline to 20 stages. The deeper pipeline enables instructions to be queued and executed at the fastest-possible rate, increasing performance, frequency, and scalability. Hyper-Threading TechnologyHyper-Threading Technology (HT Technology) is a technology that boosts computing performance, by enabling a single processor to function as two "virtual" processors by executing two threads in parallel, allowing you and your software to multi-task more effectively. More information. IEEE (Institute of Electrical and Electronics Engineers)The IEEE ( www.ieee.org) is a membership organization based in New York that includes engineers, scientists and students in electronics and allied fields. It has more than 300,000 members and is involved with setting standards for computers and communications. IETF (Internet Engineering Task Force)IETF is a large open international community of manufacturers, network designers, operators, and researchers that develop and monitor the standards for the Internet, its architecture and operation. I/O (input/output)I/O describes any program, operation or device that transfers data to or from a computer and to or from a peripheral device. For every input, there's an output. Some devices such as a keyboard or mouse are input-only devices while others like printers are output-only. The transfer of data to and from the processor to memory, expansions slots and the motherboard is also known as I/O. IP (Internet Protocol)An Internet Protocol (IP) is the rules and encoding specifications for sending data. It also determines whether the network uses a peer-to-peer or client/server architecture. The current version of IP is IPv4. A new version, called IPv6 is under development. IP AddressAn IP address is a 32-bit number that identifies each sender or receiver of information across the Internet. An IP address has two parts: an identifier of a particular network on the Internet and an identifier of the particular device (which can be a server or a workstation) within that network. IP TelephonyIP (Internet Protocol) telephony is a technology that supports voice, data and video transmission via IP-based LANs, WANs, and the Internet. This includes VoIP (Voice over IP). IPX-SPX/IPX (Internetwork Packet Exchange - Internetwork Packet Exchange/Sequenced Packet Exchange)IPX is a networking protocol used by Novell NetWare* operating systems. Like UDP/IP, IPX is a datagram protocol used for connectionless communications. Higher-level protocols, such as SPX (Sequenced Packet Exchange) and NCP (Netware Core Protocol), are used for additional error recovery services. IrDA (Infrared Data Association)The IrDA is a group of device manufacturers that developed a standard for transmitting data via infrared light waves. ISA (Industry Standard Architecture)ISA is the Industry Standard Architecture for system buses. In the early 1990's, ISA PCI local bus architecture started replacing ISA. Most computers today do not include the ISA bus. ISDN (Integrated Services Digital Network)ISDN is a type of bandwidth Internet connection that provides digital service from the customer's premises to the dial-up telephone network. ISDN uses standard telephone service copper wiring to deliver voice, data or video. ISO (International Standards Organization) Network ModelDeveloped by the International Standards Organization, the ISO network model specifies seven layers of communications protocol. Standardizing these layers and the interfaces in between them makes it possible to modify different portions of a given protocol as technologies advance or systems requirements change while maintaining a stable general protocol model. The seven layers are: Physical Data Link Network Transport Session Presentation Application The 802.11 standard encompasses the physical layer (PHY) and the lower portion of the data link layer. The lower portion of the data link layer is often referred to as the Media Access Control (MAC) sublayer. ISS (Internet Security Systems)ISS is a software application that allows all the PCs on a network simultaneous access to the Internet through a single connection and ISP (Internet Service Provider) account. iLink*iLink is Sony's term for IEEE1394 technology, (originally called Firewire* by Apple). This high-speed communication technology provides a bandwidth of about 400 Mbps. New versions of IEEE1394 will greatly broaden the bandwidth. Infrastructure ModeA wireless network can be set up as an ad hoc network or as infrastructure. In infrastructure mode, the wireless network uses an Access Point (AP) to connect wireless-enabled PCs to the wired LAN and to each other. The AP is a hub for all wireless network adapters it communicates with. Intel® MMX™ TechnologyIntel® MMX™ technology is designed to accelerate multimedia and communications applications. The technology includes new instructions and data types that allow applications to achieve a new level of performance. It exploits the parallelism inherent in many multimedia and communications algorithms, yet maintains full compatibility with existing operating systems and applications. Intel® NetBurst® micro-architectureThe NetBurst® micro-architecture delivers a number of new and innovative features including Hyper Pipelined Technology, 400 MHz System Bus, Execution Trace Cache, and Rapid Execution Engine. It also delivers a number of enhanced features, including Advanced Transfer Cache, Advanced Dynamic Execution, Enhanced Floating Point and Multimedia Unit, and Streaming SIMD Extensions 2. Intel SpeedStep® TechnologyIntel SpeedStep® technology lets you customize high performance computing on your mobile PC. When the laptop computer is connected to the AC outlet, the mobile PC runs the most complex business and Internet applications with speed virtually identical to a desktop system. When powered by a battery, the processor drops to a lower frequency (by changing the bus ratios) and voltage, conserving battery life while maintaining a high level of performance. Manual override lets you boost the frequency back to the high frequency when on battery. Intel® XScale™ technology-based processorsA line of Intel® processors designed to optimize low-power consumption and high-performance processing for a wide range of wireless and networking applications and rich services. Internet Streaming SIMD ExtensionsConsists of 70 instructions and includes single instruction, multiple data for floating-point, additional SIMD-integer and cacheability control instructions. Benefits include higher resolution image viewing and manipulation, high quality audio, MPEG2 video, and simultaneous MPEG2 encoding and decoding, reduced CPU utilization for speech recognition, and higher accuracy and faster response times. Internet ApplianceAn Internet appliance is computer that is intended primarily for Internet access, is simple to set up and usually does not support installation of third-party software. These computers generally offer customized Web browsing, touch-screen navigation, e-mail services, entertainment and personal information management applications. An Internet appliance can be Wi-Fi enabled or it can be connected via a cable to the local network. LAN (Local Area Network)A LAN is a computer network that spans a relatively small area and usually connects workstations and personal computers so users can communicate with each other, share data or access devices such as laser printers. When several LANs are connected together via telephone lines or radio waves, they're known as a wide-area network (WAN). The emerging wireless networking standard for LAN is 802.11a with data rates up to 54 Mbps versus 11 Mbps for the 802.11b standard. 802.11a enables more simultaneous wireless users and enhanced mobile multimedia applications such as streaming video. In addition, the 802.11a standard operates in the 5 GHz band which is free of congestion, reducing interference with cordless phones. LAN PartyLocal Area Network (LAN) party consist of gamers meeting in a central location - a private home, office building, conference center, etc. - to play or compute using PC games. Everyone brings their own computer (mobile or desktop), which are networked together then connected, to a local server using a LAN rather than modems linked to the Internet. Gameplay is extremely fast and interactive because players are within close proximity of each other. Level 1 Execution Trace CachePart of the Pentium® 4 processor's Intel® NetBurst® micro-architecture. In addition to the 8 KB data cache, the Pentium 4 processor includes an Execution Trace Cache that stores up to 12 K decoded micro-ops in the order of program execution. This increases performance by removing the decoder from the main execution loop and makes more efficient usage of the cache storage space since instructions that are branched around are not stored. As a result, a high volume of instructions are delivered to the processor's execution units and the overall time required to recover from erroneous branch predictions is decreased. Level 2 Advance Transfer CacheThe 256 KB Level 2 Advance Transfer Cache (ATC) delivers a much higher data throughput channel between the Level 2 cache and the processor core. 512 KB L2 Advance Transfer Cache is available on 0.13 micron technology Pentium® 4 processors, while 0.18 micron technology Pentium 4 processors utilize a 256 KB L2 Advance Transfer Cache. Features of the ATC include: Non-Blocking, full speed, on-die level 2 cache, 8-way set association, 512-bit or 256-bit data bus to the level 2 cache, data clocked into and out of the cache every clock cycle. Levels of TrustLevel 1 - Harden the base platform and system softwareLevel 2 - Trusted operating system, applications and solution stack.Level 3 - Trusted I/O and communicationsLevel 4 - Trusted enterprise Level "X" - WAN, appliances, peripheral devices and beyond Look-up TableA look-up table can either be a translation table that determines the routing 'instructions' for a call or it can also be a set of addresses (source and destination) used by a bridge or router to determine where to send a packet of data, which may be video, audio, etc. Low VoltProcessors that bring Intel performance and great battery life to a new class of super-thin and light mini-laptops. MAC (Media Access Control)A MAC is a unique identifier used to provide security for wireless networks. Every wireless 802.11 device has its own MAC address hard-coded into it. When a network uses a MAC table, only those 802.11a radios whose MAC addresses are entered in that table can operate over the network. MAN (Metropolitan Area Network)The MAN is a high-speed network used within a town or city. A MAN typically provides very high-speed connections, using fiber-optic cable or other digital media, between LANs in the same area. An example is AbMAN, the Aberdeen Metropolitan Area Network (www.abman.ent.uk). More recently, in a growing number of communities, 802.11b-based WLANs have interconnected to form wireless MANs using inexpensive antenna systems and consumer-level 802.11b and 802.11a wireless equipment. An example is Personal Telco (www.personaltelco.net). MMORPG (Massively Multiplayer Online Role-Playing Games)Massively Multiplayer Online Role-Playing Games are played online over a network or the Internet by more than one player. Today's MMORPG can support several thousands players at once. MPEG (Moving Picture Experts Group)MPEG is the name of a family of standards used for coding audio-visual information (e.g., movies, video, music) in a digital compressed format. The major advantage of MPEG compared to other video and audio coding formats is that MPEG files are much smaller for the same quality. This is because MPEG uses very sophisticated compression techniques. MaskingMasking means to "cover up," which is what occurs when a loud sound is overlaid off a softer one. The latter is masked. Micro-architectureThe architecture of a processor refers to the instruction set, registers, and memory-resident data structures that are public to a programmer and are maintained and enhanced from one generation of architecture to the next. The micro-architecture of a processor refers to implementation of a processor architecture in silicon. Within a family of processors, like the Intel IA-32 processors, the micro-architecture typically changes from one processor generation to the next, while implementing the same public processor architecture. Intel's IA-32 architecture is based on the x86 instruction set and registers. It has been enhanced and extended through generations of IA-32 processors, while maintaining backwards compatibility for code written to run on the earliest IA-32 processors. Mobile IPIETF-defined protocol that allows mobile devices to maintain persistent IP sessions and IP address as the user moves the device from subnet to subnet within a network or changes networks. MotherboardSometimes called the system board or main board, the motherboard is the main circuit board of a PC. The motherboard typically contains the processor (or CPU), BIOS (basic input/output system), memory, mass storage interfaces, serial and parallel ports, expansion slots, and all the controllers required to communicate with standard peripheral devices, such as the display screen, mouse, keyboard and disk drive. Collectively, some of the chips which reside on the motherboard are known as the motherboard's chipset. MP3The file extension for the audio layer (layer 3) of a MPEG file is MP3. This layer uses perceptual (what can be heard) audio coding and psychoacoustic compression to remove redundant or irrelevant sound signals. It then adds a filter bank known as a Modified Discrete Cosine Transform (MDCT), which increases the resolution of the frequency. The resulting file is shrunk by a factor of 12 (from 1411.2 kbps to 112-128 kbps) without sacrificing sound quality. MP3 files are small enough to easily transfer across the Internet. mp3PROThe generation of MP3 compression, mp3PRO files are smaller with higher fidelity or sound quality. They are also backward compatible with the standard MP3 format. MultimodalMultimodal technology allows users to utilize multiple forms of input and output – including voice, keypads and stylus – interchangeably in the same interaction. MultithreadedA multithreaded program allows different parts of a program to run concurrently. Operating systems like Windows .Net* and Windows XP* are multithreaded as are many scientific applications. When creating an application, developers must create code so that the threads can run independently and will not interfere with each other. NAT (Network Address Translation)NAT is a network capability that enables a houseful of computers to dynamically share a single incoming IP address from a dial-up, cable or DSL connection. NAT takes the single incoming IP address and creates a new IP address for each client computer on the network. NIC (Network Interface Card)A NIC is a type of PC adapter card that either works without wires (Wi-Fi) or attaches to a network cable to provide two-way communication between a computer and network devices such as a hub or switch. Most office-wired NICs operate at 10 Mbps (Ethernet), 100 Mbps (Fast Ethernet) or 10/100 Mbps dual speed. High-speed Gigabit and 10 Gigabit NIC cards are also available. (See PC Card.) Network NameA network name identifies a wireless network to all its shared components. During installation of most wireless networks, you must enter the network name or SSID. Different network names are used when setting up your individual computer, a wired network, or a workgroup. Non-blocking Level 1 CacheLevel 1 (L1) cache is a high-speed storage mechanism that is built into the architecture of a microprocessor. Non-blocking consists of two separate 16 KB L1 caches, one for instruction and one for data to provide fast access to recently used data and instructions. Open SourceWhen the source code of a computer program is made available free of charge to the general public, it's known as open source. The basis of open source software is to produce more useful and bug-free products for everyone to use. The concept relies on peer review to find and eliminate bugs in the program code, a process which commercially developed and packaged programs do not utilize. The Open Source Initiative (OSI) reviews then certifies open source programs. They have a stringent list of criteria that include making sure no one collects a royalty on the software and no person, group or field of endeavor can be denied access to the program. OptimizationOptimization consists of analyzing and tuning software code to make it perform faster and more efficiently on Intel processor architecture. OptoelectronicsOptoelectronics involves the manufacture of hardware devices that convert electrical signals into photon (or light) signals and vice versa. Examples of optoelectronic technologies are fiber optic communications, laser systems, electric eyes, remote sensing systems, medical diagnostic systems and optical information systems. P6 micro-architectureInternal chip architecture of the Pentium® III processors and Celeron® D processors. It's features include: multiple branch prediction, which predicts program execution through multiple branches and accelerates the flow of work to the processor; dataflow analysis, which creates an optimized, reordered schedule of instructions by analyzing data dependencies between instructions; and speculative execution, which carries out instruction execution speculatively and based upon this optimized schedule, ensures that the processor's superscalar execution units remain busy, boosting overall performance. PAN (Personal Area Network)The PAN is a wireless LAN with a very short range (up to 10 meters). PANs are used to connect devices, such as a PDA, keyboard, mouse, printer, etc. that a single person uses with their computer. PANs enable easier interconnection between devices by eliminating cables. Bluetooth* is a technology commonly used to form a PAN. PCI (Peripheral Component Interconnect)Developed by Intel, PCI is a local bus standard. A bus is a channel used to transfer data to (input) and from (output) a computer and to or from a peripheral device. Most PCs have a PCI bus usually implemented at 32-bits providing a 33 MHz clock speed with a throughput rate of 133 MBps. PCI ExpressPCI Express is a 3rd generation I/O architecture where ISA and PCI were respectively the 1st and 2nd generations. A high-speed, general-purpose serial I/O interconnect, PCI Express will initially offers speeds of 2.5 Gigabits per second, support multiple widths ("lanes" of data that range from 1 to 32), and scale to the limits of copper. PCI Express will unify I/O architecture for desktop, mobile, server, communications platforms, workstations and embedded devices while also coexisting with PCI and USB connection types. PCMCIA (Personal Computer Memory Card International Association)PCMCIA is an organization of about 500 companies that developed the standard for small, credit card-sized devices, commonly referred to as PC Cards. PHY (PHYsical Transport Medium)PHY designates the lowest protocol layer specified by the OSI Network Model. It deals primarily with transmission of the raw bit stream over the PHYsical transport medium. In the case of wireless LANs, the transport medium is free space. The PHY defines such parameters as data rates, modulation method, signaling parameters and transmitter/receiver synchronization. Within an actual radio implementation, the PHY corresponds to the radio front end and baseband signal processing sections. PackageAn enclosure for a single element, integrated circuit, or hybrid circuit. It provides hermetic or nonhermetic protection, determines the form factor, and serves as the first-level interconnection externally for the device by means of package terminals. PacketA portion of a message transmitted over a packet-switching network. One of the key features of a packet is that it contains the destination address in addition to the data. Peer-to-Peer NetworkA peer-to-peer network is a wireless or wired computer network that has no server, central hub or router. All the networked PCs are equally able to act as a network server or client. Each client computer can talk to all the other wireless computers without going through an Access Point or hub. However, since there is no central base station to monitor traffic or provide Internet access, the various signals can collide, reducing overall performance. Performance AnalyzerA performance analyzer is used to pinpoint areas in software code that are using excess CPU cycles. Once identified, these areas can be optimized to run more efficiently. The Intel® VTune™ Performance Analyzer enhances the performance of applications running on the latest Intel processors. PC CardA PC card is a removable, credit-card-sized memory or I/O device that fits into a Type II PCMCIA standard slot. PC Cards are used primarily in laptop computers and PDAs. PC Card peripherals include Wi-Fi cards, memory cards, modems, NICs, hard drives, and so on. PhysicsPhysics are the mathematical calculations designed to create realism that mimics the real world in graphically-intensive applications like PC games, animation and simulation such as car crashes. PixelPixel is an abbreviation of Picture Element, which is a single point of a graphic image. The number of bits needed to represent each pixel determines how many colors or shades of gray can be displayed. For example, in 8-bit color mode, the color monitor uses 8 bits for each pixel, making it possible to display 2 to the 8th power (256) different colors or shades of gray. Power ManagementRefers to how power is efficiently directed to different components of a system. Power management is especially important for portable devices that rely on battery power. By reducing power to components that aren't being used, a good power management system can double or triple the lifetime of a battery. ProcessorThe processor (aka CPU or microprocessor) is the brain of your computer. It reads instructions from your software and tells your computer what to do. The speed at which the CPU processes information internally is measured in MegaHertz (MHz) and GigaHertz (GHz). 1 GHz is equal to 1,000 MHz. Generally, processors with higher MHz or GHz enhance your ability to run creative, entertainment, communication, and productivity applications. Processor core speedProcessor core speed is a measurement, in millions, of the number of times the processor cycles in one second. Generally, processors with higher MHz or GHz enhance your ability to run creative, entertainment, communication, and productivity applications. Proxy ServerA proxy server is used in larger companies and organizations to improve network operations and security. It can be used to prevent direct communication between two or more networks. The proxy server forwards allowable data requests to remote servers and/or responds to data requests directly from stored remote server data. PsychoacousticsA branch of science dealing with hearing, the sensations produced by sounds, and the problems of communication. QuickStart TechnologyExtends battery life by entering a low-power state during the briefest pauses in user activity, such as between key strokes, and returning instantly to full-power state when prompted. RAM (Random Access Memory)Memory available for storing data and programs currently being processed. It is automatically erased when the power is turned off. Can be accessed without touching preceding bytes. Intel desktop processors are extensively tested with RDRAM, PC SDRAM or DDR SDRAM, depending on which Intel® chipset is the basis for the system's motherboard. RDRAM (Rambus Dynamic Random Access Memory)Developed by Rambus Corporation,* with architecture and protocol designed to achieve high effective bandwidth and single-device upgrade granularity. The narrow, high-performance channel also offers performance and capacity scalability through the use of multiple channels in parallel. Capable of providing up to 1.600 GB/sec bandwidth per channel. The Intel® 850 chipset implements dual RDRAM memory channels to offer 3.2-gigabytes-per-second of peak memory bandwidth. Other Intel chipsets support PC133 SDRAM or DDR SDRAM. RenderingRefers to the process of adding realism to computer graphics by adding three-dimensional qualities such as shadows and variations in color and shade. One technique for rendering graphics is called ray tracing. Another type of rendering is scanline rendering, which renders images one vertical line at a time instead of object-by-object as in ray tracing. In general, scanline rendering doesn't produce as good results as ray tracing, but it is used frequently in animation packages where the image quality of each individual frame isn't so important. RF (Radio Frequency)RF covers a range of high-frequency, electromagnetic frequencies used for radio transmissions. In communications, RF signals transmit data using various methods, such as TDMA, CDMA, DSSS (direct-sequence spread spectrum), and others. WLANs, PANs, Bluetooth,* and other wireless technologies use RF signals to transmit data. RJ-45 (Registered Jack - 45)RJ-45 designates a standard connector used in Ethernet networks. Although it closely resembles a standard RJ-11 telephone connector, an RJ-45 connector can have up to eight wires, whereas telephone connectors have only four. RangeRange refers to the physical distance over which a wireless network operates reliably. Most Wi-Fi systems support a range of a hundred feet or more. Depending on the environment and the type of antenna used, Wi-Fi signals can have a range of up to one mile. Rapid Execution EnginePart of the Pentium® 4 processor's Intel® NetBurst® micro-architecture. Two Arithmetic Logic Units (ALUs) are clocked at twice the core processor frequency, allowing basic integer instructions such as Add, Subtract, Logical AND, and Logical OR to execute in half of a clock cycle. For example, the Rapid Execution Engine on a 1.50 GHz Pentium 4 processor runs at 3 GHz. Residential GatewayA residential gateway is a wireless device that connects multiple PCs, peripherals and the Internet on a home network. Most Wi-Fi residential gateways provide DHCP and NAT services, as well. RoamingIn a wireless network, roaming refers to moving from one Access Point to another without losing service or a loss in connectivity. Roaming lets users move about freely and continue to access the Internet and e-mail. RouterA router is a device that forwards data packets from one local area network (LAN) or wide area network (WAN) to another. Based on routing tables and routing protocols, routers can read the network address in each transmitted frame and choose the most efficient transmission route, depending on current traffic, line costs, speed, bad connections, and other factors. (See Wireless Router.) SBR (Spectral Band Replication) SBR is used to enhance the audio quality of highly compressed sound files, Spectral Band Replication (SBR) reconstructs the highest part of the frequency spectrum. For instance, around 60 kbps of a 64 kbps mp3PRO are encoded as conventional MP3 data. The high frequency part of the file — 8 to 16 kHz — is then reconstructed using Spectral Band Replication. SDRAM (Synchronous Dynamic Random Access Memory)SDRAM synchronizes itself with the processors bus and is capable of running at 133 MHz. The Intel® 845 chipset couples the power of the Pentium® 4 processor with PC133 SDRAM memory to provide various levels of price and performance. Other Intel chipsets use RDRAM. SGML (Standard Generalized Markup Language)Adopted by the International Standards Organization in 1986, SGML is a text-based language for describing the content and structure of digital documents. HTML evolved from SMGL. SPX (Sequenced Packet Exchange)SPX is a transport layer protocol (layer 4 of the OSI — Open System Interconnection — used in Novell Netware* networks. The SPX layer sits on top of the IPX layer (layer 3) and provides connection-oriented services between two nodes on the network. SPX is used primarily by client/server applications. Whereas the IPX protocol is similar to IP, SPX is similar to TCP. Together, therefore, IPX/SPX provides connection services similar to TCP/IP. SSE (Streaming SIMD Extensions)Internet Streaming SIMD (Single Instruction Multiple Data) Extensions are instructions that reduce the overall number of instructions required to execute a particular program task. As a result, they can boost performance by accelerating a broad range of applications, including video, speech, and image, photo processing, encryption, financial, engineering and scientific applications. NetBurst® micro-architecture adds 144 new SSE instructions, which are known as SSE2. SSID (Service Set Identifier)An SSID is the name that uniquely identifies a wireless network. Wireless Access Points broadcast the SSID so that end-users can identify the WLAN they want to connect to. Different SSIDs enable different WLANs to exist in the same physical space, and SSIDs must be identical between the wireless Access Point and the wireless network adapter to allow access to the wireless network. To enhance security in a WLAN, an administrator can turn off the broadcast function of some wireless Access Points to prevent broadcasting across the SSID. For a client to connect to the network, the end-user would have to manually enter the SSID. (See ESSID.) SSL (Secure Socket Layer)SSL is a common encryption scheme used by many online retail and banking sites to protect the financial integrity of transactions. When an SSL session begins, the server sends its public key to the browser. The browser then sends a randomly generated secret key back to the server in order to have a secret key exchange for that session. Satellite BroadbandSatellite broadband is a wireless high-speed Internet connection provided by satellites. Some satellite broadband connections are two-way: up and down. Others are one-way: the satellite provides a high-speed downlink and a dial-up telephone connection or other land-based system provides the uplink to the Internet. Site SurveyA site survey is the process whereby a wireless network installer inspects a location prior to setting up a wireless network. Site surveys are used to identify the radio- and client-use characteristics of a facility to ensure optimal placement of Access Points. Smart DisplayA wireless, pen-enabled LCD monitor that through integrated wireless capabilities extends the use of your home PC to anywhere in the house (within 100 feet). Sound CardMost computers contain sound cards, an expansion board that enables a computer to manipulate and output sounds from a CD player or through speakers. Most sound cards support Musical Instrument Digital Interface (MIDI,) a standard for representing music electronically. In addition, most sound cards are Sound Blaster-compatible, which means that they can process commands written for a Sound Blaster card, the de facto standard for PC sound. The two basic methods used by sound cards to translate digital data into analog sounds are FM Synthesis (mimics different musical instruments according to built-in formulas) and Wavetable Synthesis (produces more accurate sound by using recordings from actual instruments. Subnetwork or SubnetFound in larger networks, these smaller networks are used to simplify addressing between numerous computers. Subnets connect to the central network through a router, hub or gateway. Typically, each wireless LAN is set up to use the same subnet for all the local computers it communicates with. SwitchA switch is a network device that connects multiple computers on a LAN so they can communicate with one another, the rest of the network, and the Internet. Unlike a hub, users connected to a switch do not share the available bandwidth; each switch port runs at the full bandwidth of the switch port. Switches allow multiple PCs to be connected to the same network without losing bandwidth speed. System BusConnects the processor with the main memory, managing transfer of data and instructions between the two components. The Pentium® 4 processor supports Intel's highest performance desktop system bus by delivering 3.2 GB of data per second into and out of the processor - three times the bandwidth of previous processors. This is accomplished through a physical signaling scheme of quad pumping the data transfers over a 100-MHz clocked system bus and a buffering scheme allowing for sustained 533-MHz data transfers. TCP (Transmission Communications Protocol)TCP is a communications protocol used along with the Internet Protocol (IP) to send data in the form of individual units (called packets) between computers over the Internet. While the IP protocol handles the actual delivery of the data, TCP keeps track of the packets that a message is divided into for efficient routing through the Internet. For example, when a Web page downloads from a Web server, the TCP program layer in that server divides the file into packets, numbers the packets, and then forwards them individually to the IP program layer. Although each packet has the same destination IP address, it may get routed differently through the network. At the other end of the transmission, TCP reassembles the individual packets and waits until they have all arrived to forward them as a single file. TCP/IP (Transmission Communications Protocol/Internet Protocol)TCP/IP is the communications protocol that undergirds the Internet and communications between computers in a network. The first part, TCP, is the transport part, which matches the size of the messages on either end of a transmission and guarantees that the correct message has been received. The IP part is the user's computer address on a network. Every computer in a TCP/IP network has its own IP address that is either dynamically assigned at startup or permanently assigned. All TCP/IP messages contain the address of the destination network as well as the address of the destination station. This makes it possible to transmit TCP/IP messages to multiple networks (subnets) within an organization or worldwide. TDMA (Time Division Multiple Access)TDMA is a technology for delivering digital wireless service using time-division multiplexing (TDM). TDMA works by dividing a radio frequency into time slots and then allocating slots to multiple calls. In this way, a single frequency can support multiple, simultaneous data channels. TDMA is used by the GSM digital cellular system. TPM (Trusted Platform Module)A Trusted Platform Module is a hardware device that is connected to a platform's motherboard and is used to validate the identity and operating parameters of a computer or device used in a trusted computing environment. The TPM and the data stored within it are isolated from all other components on a platform. In addition, TPMs aren't interchangeable between platforms. TPMs protect users' data by generating a distinct digital signature that verifies the exact platform and hard drive from which data is to be accessed. TagsA tag is a command that specifies how a document or portion of a document should be formatted such as headings, paragraphs, lists, hypertext links, etc. TelephonyTelephony is the transmission of voice, data, video or image signals. It has most commonly been used to refer to the integration of the telephone with the PC or other device. Internet telephony enables people to use the Internet as the transmission medium for telephone calls. Even though Internet telephony doesn't offer the same quality as conventional telephone services, it enables users to make free telephone calls anywhere in the world. Internet telephony products are sometimes called IP telephony, Voice over the Internet (VOI) or Voice over IP (VOIP) products. ThreadA thread is part of a program that can be run independently of other aspects of the program. Trusted ComputingTrusted Computing requires transactions and computing devices to be: Trusted - Acts in a known manner and able to proactively communicate that manner Reliable - Readily available for transactions and communications, as well as prepared to act against viruses and other intrusions Safe - Able to stop unwanted intervention or observation Protected - Sharing information with only those that need to know within commonly accepted parameters for computer privacy UDP (User Datagram Protocol)UDP is a connectionless protocol used mainly for broadcasting messages over a network. Like TCP, UDP runs on top of IP networks. Unlike TCP/IP, UDP/IP provides very few error recovery services, offering instead a direct way to send and receive datagrams over an IP network. USB (Universal Serial Bus)USB is an external bus (an interconnect) standard that supports data transfer rates of 12 Mbps. A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems and keyboards. Introduced in 1996, USB has completely replaced serial and parallel ports. It also supports plug-and-play installations and hot plugging. USB 2.0, which supports data transfer rates of 480 Mbps, was introduced in 2002 for Microsoft Windows XP.* Ultra Low VoltFor the ultimate in portability. Processors that bring Intel performance and great battery life to a new class of super-thin and light sub-laptops. VoIP (Voice Over Internet Protocol)VoIP allows players to speak to one another through their PCs while continuing to play. Unlike voice recognition, which parses incoming voice signals from players, recognizes certain words and phrases then triggers events based on what was spoken, VoIP captures, compresses then broadcasts over a LAN or the Internet complete and accurate exchanges between players. VPN (Virtual Private Network)A VPN is a secure Internet connection using encryption and tunneling protocols to create a safe connection, or tunnel, to a private network. VPNs provide highly secure connections between remote clients, such as branch offices or traveling personnel, and a central office. A variety of VPN routers is available for both home and office use. Video GraphicsVideo graphics are the text and images displayed on a computer monitor. A video card or board is used to generate and send text (ASCII characters) and graphics (bit-mapped images) to the monitor. The resolution of a video card determines how many colors can be displayed. Many video cards contain memory and graphics coprocessors that perform graphics calculations, which were previously done by the processor. VTuneThe Intel® VTune™ Performance Analyzer is used to determine how software performs when run on a specific processor such as the Intel® Pentium® 4 processor. Software developers can then optimize their software to utilize a processor's features such as SSE2. War DriverAny person who finds and potentially exploits unsecured wireless LANs. War drivers use network detection software to find homes or office buildings with open access. They park outside of unsecured buildings or homes and use a wireless laptop and an antenna to access the network, get free Internet access, or gain access to network data. WAN (Wide Area Network)A WAN connects LANsand MANs over great distances, such as across the country and around the world. The WAN is built on the services of "long-haul" communications carriers, such as Sprint* and UUNET*, who use fiber-optic cable, satellite, and other high-speed communications technologies. WAVDeveloped by Microsoft and IBM, WAV is the de facto standard format for storing sound files on PCs. WAV sound files end with the a .wav extension and can be placed on nearly all Windows-based PCs. WEP (Wired Equivalent Privacy) EncryptionWEP is a standard used to encrypt wireless transmissions to protect data in transit. WEP provides users with secure connections in a WLAN environment. WEP offers different levels of encryption, from 40-bit to a higher security rating of 128-bit encryption. WEP must be enabled in the Wireless Access Point and client network adapter to ensure encrypted transmissions. Wi-Fi (Wireless Fidelity)Wi-Fi is a name applied to equipment that complies with the802.11b wireless standard, as defined by Wi-Fi Alliance. Wi-Fi logos help identify wireless networking components that are certified to work in 802.11b WLANs. WISP (Wireless Internet Service Provider)A Wireless Internet Service Provider provides Internet services to homes and business using wireless networking technology, including 802.11a/b. WISP customers communicate with their WISP using an antenna. In some cases, the antenna on the wireless network adapter is all a user needs to communicate with their WISP. In many cases, however, users must install an external antenna. Hotspot operators (HSOs) are WISPs, providing Internet services to customers in small areas, such as a hotel, airport, or coffee shop. WISPs make the Internet accessible to users in outlying areas, where DSL and cable Internet are not available. WLAN (Wireless Local Area Network)A WLAN is a wireless implementation of a LAN that allows users to move around with their device. WLANs provide the same connectivity features as a LAN, but usually at 11 Mbps for 802.11b; 54 Mbps for 802.11a. WLANs are commonly based on the 802.11 standard. WLANs enable users to quickly build a network of computers without installing cables, freeing them to move from place to place without losing connectivity. Wireless GatewayA wireless gateway is a wireless Access Point that provides a central connection between a wireless network and other networks, including the Internet. Wireless gateways can provide important services, such as network address translation (NAT) and firewalling. A wireless gateway is an essential part of a home or small business wireless network when connecting to the Internet through broadband technologies such as DSL or cable. Wireless PC CardA wireless PC card is an 802.11 WLAN adapter that fits into a PCMCIA slot in a laptop or desktop computer. Wireless PC cards enable a user to connect to a wireless network. A wireless PC card and a PC can also be used to share an Internet connection with a WLAN. Wireless Print ServerA wireless print server connects users on a wireless network to a printer without the need for cables. Print data is transmitted across the WLAN to the wireless print server where it is queued for printing. Wireless print servers enable quick and easy installation of printers anywhere within a WLAN area. Wireless RouterA wireless router is a network device that routes IP traffic across several wireless IP networks and wired networks. Wireless routers are used to build independent WLANs that can communicate with each other and the Internet. Some Access Points can function either as a wireless gateway or wireless router, while other devices function solely as a Wireless Router. (See Router.) Wireless USB Network AdapterA wireless USB network adapter is a wireless network adapter that connects a computer to a wireless network using the computer's USB port instead of plugging into the CardBus or the PCI bus. (See also Wireless PC Card.) A wireless USB network adapter provides the same functionality as a wireless PC card or an internal wireless network adapter, but is quicker to install and can be moved from one computer to another. XHTML (Extensible Hypertext Markup Language)eXtensible Hypertext Markup Language (XHTML) combines the strength of HTML with the power of XML, It is designed for Web clients that do not support the full set of XHTML features; for example, Web clients such as mobile phones, PDAs, pagers, and settop boxes. In addition, XHTML provides the framework for future extensions of HTML. XML (eXtensible Markup Language)A pared down version of SGML, eXtensible Markup Language (XML) enables designers to create their own customized tags to provide functionality not available with HTML.