Technical Glossary

A

ADSL - Stands for "Asymmetric Digital Subscriber Line." ADSL is a type of DSL, which is a method of transferring data over copper telephone lines. While symmetrical DSL (SDSL) uploads and downloads data at the same speed, ADSL has different maximum data transfer rates for uploading and downloading data.

ALU - Stands for "Arithmetic Logic Unit." An ALU is an integrated circuit within a CPU or GPU that performs arithmetic and logic operations. Arithmetic instructions include addition, subtraction, and shifting operations, while logic instructions include boolean comparisons, such as AND, OR, XOR, and NOT operations.

Analog - As humans, we perceive the world in analog. Everything we see and hear is a continuous transmission of information to our senses. This continuous stream is what defines analog data. Digital information, on the other hand, estimates analog data using only ones and zeros.

ANSI - Stands for "American National Standards Institute." ANSI's primary goal is to enhance the global competitiveness of U.S. businesses and to improve the American quality of life by promoting and facilitating voluntary consensus standards and conformity assessment systems.

ASCII - Stands for "American Standard Code for Information Interchange." ASCII is the universal standard for the numerical codes computers use to represent all upper and lower-case letters, numbers, and puctuation. Without ASCII, each type of computer would use a different way of representing letters and numbers, causing major chaos for computer programmers (allowing them even less sleep than they already get).

Avatar - Generally speaking, an avatar is the embodiment of a person or idea. However, in the computer world, an avatar specifically refers to a character that represents an online user. Avatars are commonly used in multiplayer gaming, online communities, and Web forums.

B

Bandwidth - Bandwidth refers to how much data you can send through a network or modem connection. It is usually measured in bits per second, or "bps." You can think of bandwidth as a highway with cars travelling on it. The highway is the network connection and the cars are the data. The wider the highway, the more cars can travel on it at one time. Therefore more cars can get to their destinations faster. The same principle applies to computer data -- the more bandwidth, the more information that can be transferred within a given amount of time.

Barebones - A barebones PC is a computer that has minimal components. A typical barebones system includes a case, motherboard, CPU, hard drive, RAM, and power supply. Most barebones systems are sold as kits, in which the components must be assembled by the user.

Base Station - The term "base station" was first used to refer to the towers you see on the side of the road that relay cell phone calls. These stations handle all cellular calls made within their area, receiving information from one end of the call and transmitting it to the other.

Baud - Contrary to popular belief, baud is not a direct measurement of data transfer speed, but instead it measures how many electrical signals are sent per second. Baud is used to measure the rate of electrical signals, or "signaling elements," for modems, networks, serial cables, and other data transfer mediums.

Binary - Binary is a two-digit (Base-2) numerical system, which computers use to store data and compute functions. The reason computers use the binary system is because digital switches inside the computer can only be set to either on or off, which are represented by a 1 or 0. Though the binary system consists of only ones and zeros, the two digits can be used to represent any number.

BIOS - Stands for "Basic Input/Output System." Most people don't need to ever mess with the BIOS on a computer, but it can be helpful to know what it is. The BIOS is a program pre-installed on Windows-based computers (not on Macs) that the computer uses to start up. The CPU accesses the BIOS even before the operating system is loaded. The BIOS then checks all your hardware connections and locates all your devices.

Bit - The computer term "bit" comes from the phrase "Binary DigIT," which is different than that thing you put around a horse's mouth. A bit is a single digit number in base-2 (a zero or a one) and is the smallest unit of computer data.

Bitrate - Bitrate, as the name implies, describes the rate at which bits are transferred from one location to another. In other words, it measures how much data is transmitted in a given amount of time. Bitrate is commonly measured in bits per second (bps), kilobits per second (Kbps), or megabits per second (Mbps).

Blu-ray - Blu-ray is an optical disc format such as CD and DVD. It was developed for recording and playing back high-definition (HD) video and for storing large amounts of data. While a CD can hold 700 MB of data and a basic DVD can hold 4.7 GB of data, a single Blu-ray disc can hold up to 25 GB of data.

Bluetooth - This wireless technology enables communication between Bluetooth-compatible devices. It is used for short-range connections between desktop and laptop computers, PDAs (like the Palm Pilot or Handspring Visor), digital cameras, scanners, cellular phones, and printers.

Boot Disk - A boot disk is actually not a computer disk in the shape of a boot. If it was, most disk drives would have a difficult time reading it. Instead, a boot disk is a disk that a computer can start up or "boot" from. The most common type of boot disk is an internal hard drive, which most computers use to start up from. The operating system installed on the hard drive is loaded during the boot process.

Botnet - A botnet is a group of computers that are controlled from a single source and run related software programs and scripts. While botnets can be used for distributed computing purposes, such as a scientific processing, the term usually refers to multiple computers that have been infected with malicious software.

Bridge - When a road needs to extend across a river or valley, a bridge is built to connect the two land masses. Since the average car cannot swim or fly, the bridge makes it possible for automobiles to continue driving from one land mass to another. In computer networking, a bridge serves the same purpose. It connects two or more local area networks (LANs) together.

Broadband - This refers to high-speed data transmission in which a single cable can carry a large amount of data at once. The most common types of Internet broadband connections are cable modems (which use the same connection as cable TV) and DSL modems (which use your existing phone line). Because of its multiple channel capacity, broadband has started to replace baseband, the single-channel technology originally used in most computer networks.

Buffer - A buffer contains data that is stored for a short amount of time, typically in the computer's memory (RAM). The purpose of a buffer is to hold data right before it is used.

Bus - While the wheels on the bus may go "round and round," data on a computer's bus goes up and down. Each bus inside a computer consists of set of wires that allow data to be passed back and forth. Most computers have several buses that transmit data to different parts of the machine. Each bus has a certain size, measured in bits (such as 32-bit or 64-bit), that determines how much data can travel across the bus at one time. Buses also have a certain speed, measured in megahertz, which determines how fast the data can travel.

Byte - A byte is a set of 8 bits that represent a single character in the computer's memory. Do not confuse this term with "bite," as in taking a bite of a cookie, because that is totally different. While bits are often used to measure data transfer speeds, bytes are used to measure file sizes, hard disk space, and computer memory. Larger amounts of data are measured in units such as megabytes, gigabytes, and terabytes. For example, one kilobyte is equal to 1,024 bytes.

C

Cache - This term is pronounced like "cash" -- not "catch," and definitely not "cashé." There are many different types of caches but they all serve the same purpose. A cache stores recently-used information in a place where it can be accessed extremely fast. For example, a Web browser like Internet Explorer uses a cache to store the pages, images, and URLs of recently visted Web sites on your hard drive.

Captcha - A captcha is program used to verify that a human, rather than a computer, is entering data. Captchas are commonly seen at the end of online forms and ask the user to enter text from a distorted image. The text in the image may be wavy, have lines through it, or may be highly irregular, making it nearly impossible for an automated program to recognize it.

CD - Stands for "Compact Disc." CDs are circular discs that are 4.75 in (12 cm) in diameter.

CD-R - Stands for "Compact Disc Recordable." CD-R discs are blank CDs that can record data written by a CD burner.

CD-RW - Stands for "Compact Disc Re-Writable." A CD-RW is a blank CD that can be written to by a CD burner. Unlike a CD-R (CD-Recordable), a CD-RW can be written to multiple times.

CDMA - Stands for "Code Division Multiple Access." CDMA is a wireless transmission technology that was developed during World War II by the English allies to avoid having their transmissions jammed. After the war ended, Qualcomm patented the technology and made it commercially available as a digital cellular technology.

Chipset - A chipset describes the architecture of an integrated circuit. This includes the layout of the circuitry, the components used within the circuit, and the functionality of the circuit board. For example, the chipset of a modem card is much different than the chipset of a computer's CPU.

Clock Speed - Clock speed is the rate at which a processor can complete a processing cycle. It is typically measured in megahertz or gigahertz. One megahertz is equal to one million cycles per second, while one gigahertz equals one billion cycles per second. This means a 1.8 GHz processor has twice the clock speed of a 900 MHz processor.

Cloud Computing - Cloud computing refers to applications and services offered over the Internet. These services are offered from data centers all over the world, which collectively are referred to as the "cloud." This metaphor represents the intangible, yet universal nature of the Internet.

CMOS - Stands for "Complementary Metal Oxide Semiconductor." This technology is typically used in making transistors. The "complementary" part of the term unfortunately does not mean these semiconductors are free. Instead, it refers to how they produce either a positive or negative charge. Because CMOS-based transistors only use one charge at a time, they run efficiently, using up very little power. This is because the charges can stay in one state for a long period of time, allowing the transistor to use little or no power except when needed.

Cookie - A cookie is a small amount of data generated by a website and saved by your web browser. Its purpose is to remember information about you, similar to a preference file created by a software application.

CPU - Stands for "Central Processing Unit." This is the pretty much the brain of your computer. It processes everything from basic instructions to complex functions.

CRT - Stands for "Cathode Ray Tube." CRT is the technology used in traditional computer monitors and televisions. The image on a CRT display is created by firing electrons from the back of the tube to phosphors located towards the front of the display. Once the electrons hit the phosphors, they light up and are projected on the screen. The color you see on the screen is produced by a blend of red, blue, and green light, often referred to as RGB.

Cyberspace - Unlike most computer terms, "cyberspace" does not have a standard, objective definition. Instead, it is used to describe the virtual world of computers. For example, an object in cyberspace refers to a block of data floating around a computer system or network. With the advent of the Internet, cyberspace now extends to the global network of computers. So, after sending an e-mail to your friend, you could say you sent the message to her through cyberspace.

D

DAC - Stands for "Digital-to-Analog Converter" and is often pronounced "dac." Since computers only recognize digital information, the output produced by computers is typically in digital format. However, some output devices only accept analog input, which means a digital-to-analog converter, or DAC, must be used.

Daemon - The word "daemon" actually comes from the Greek language, meaning an "inner or attendant spirit" (Oxford American Dictionary). This is a fitting name, as a computer daemon is a constantly running program that triggers actions when it receives certain input.

Data Transfer Rate - The data transfer rate is commonly used to measure how fast data is transferred from one location to another. For example, a hard drive may have a maximum data transfer rate of 480 Mbps, while your ISP may offer an Internet connection with a maximum data transfer rate of only 1.5 Mbps.

Database - A database is a data structure that stores organized information. Most databases contain multiple tables, which may each include several different fields. For example, a company database may include tables for products, employees, and financial records. Each of these tables would have different fields that are relevant to the information stored in the table.

DDR - Stands for "Double Data Rate." It is an advanced version of SDRAM, a type of computer memory. DDR-SDRAM, sometimes called "SDRAM II," can transfer data twice as fast as regular SDRAM chips.

DDR2 - Stands for "Double Data Rate 2." DDR2 RAM is an improved version of DDR memory that is faster and more efficient. Like standard DDR memory, DDR2 memory can send data on both the rising and falling edges of the processor's clock cycles.

Defragment - Adding and deleting files from your hard disk is a common task. Unfortunately, this process is not always done very efficiently. For example, when you delete a bunch of little files and add a new large file, the file may get broken up into mulitple sections on the hard disk. The computer will still read the newly added file as a single valid file, but the drive will have to scan multiple parts of the disk to read it. Because hard disk seek time is one of the most significant bottlenecks in a computer's performance, this can drag down your computer's speed quite a bit.

Denial of Service - A denial of service attack is an effort to make one or more computer systems unavailable. It is typically targeted at web servers, but it can also be used on mail servers, name servers, and any other type of computer system.

DHCP - Stands for "Dynamic Host Configuration Protocol." A network server uses this protocol to dynamically assign IP addresses to networked computers. The DHCP server waits for a computer to connect to it, then assigns it an IP address from a master list stored on the server.

Dial-up - Dial-up refers to an Internet connection that is established using a modem. The modem connects the computer to standard phone lines, which serve as the data transfer medium.

Digital - Digital information is stored using a series of ones and zeros. Computers are digital machines because they can only read information as on or off - 1 or 0. This method of computation, also known as the binary system, may seem rather simplistic, but can be used to represent incredible amounts of data.

DIMM - Stands for "Dual In-Line Memory Module." It is a type of computer memory. A DIMM is a small circuit board that holds memory chips. It uses a 64-bit bus to the memory, whereas a single in-line memory module (SIMM) only has a 32-bit path. This allows DIMMs to transfer more data at once.

DirectX - DirectX is a set of standard commands and functions that software developers can use when creating their programs. While any Windows-based software program can include DirectX commands, they are usually used in video games. For example, developers may use DirectX for controlling video playback, sound effects, and peripheral input (such as a keyboard, mouse, or joystick).

Disk Drive - A disk drive is a device that reads and/or writes data to a disk.

Disk Image - A disk image is a software copy of a physical disk. It saves the entire data from the disk, including the file structure and all files and folders from the disk, in a single file. Because disk images are exact copies, or "clones," of original disks, they can be used to duplicate disks or serve as full backups in case a system restore must be done.

DLL - Stands for "Dynamic Link Library." A DLL (.dll) file contains a library of functions and other information that can be accessed by a Windows program.

DMA - Stands for "Direct Memory Access." DMA is a method of transferring data from the computer's RAM to another part of the computer without processing it using the CPU.

DNS - Stands for "Domain Name System." The primary purpose of DNS is to keep Web surfers sane. Without DNS, we would have to remember the IP address of every site we wanted to visit, instead of just the domain name.

Domain - This is the name that identifies an Web site. For example, "microsoft.com" is the domain name of Microsoft's Web site.

DOS - Stands for "Disk Operating System." DOS was the first operating system used by IBM-compatible computers. DOS uses a command line, or text-based interface, that allows the user to type commands.

DPI - Stands for "Dots Per Inch." DPI is used to measure the resolution of an image both on screen and in print. As the name suggests, the DPI measures how many dots fit into a linear inch. Therefore, the higher the DPI, the more detail can be shown in an image.

DRAM - Stands for "Dynamic Random Access Memory." DRAM is a type of RAM that stores each bit of data on a separate capacitor. This is an efficient way to store data in memory, because it requires less physical space to store the same amount of data than if it was stored statically.

DSL - Stands for "Digital Subscriber Line." It is medium for transferring data over regular phone lines and can be used to connect to the Internet. However, like a cable modem, a DSL circuit is much faster than a regular phone connection, even though the wires it uses are copper like a typical phone line.

Dual-Core - A dual-core processor is a CPU with two processors or "execution cores" in the same integrated circuit. Each processor has its own cache and controller, which enables it to function as efficiently as a single processor. However, because the two processors are linked together, they can perform operations up to twice as fast as a single processor can.

DVD - Stands for "Digital Versatile Disc." It can also stand for "Digital Video Disc," but with the mulitple uses of DVDs, the term "Digital Versatile Disc" is more correct. A DVD is a high-capacity optical disc that looks like a CD, but can store much more information. While a CD can store 650 to 700 MB of data, a single-layer, single-sided DVD can store 4.7 GB of data.

DVD+R - Stands for "Digital Versatile Disc Recordable." DVD+R discs look the same as regular DVDs, but can be used to record data. Single-sided, single-layer DVD+R discs can store 4.7GB of data, while double-layer discs can store 8.5GB and double-sided DVD-Rs can store 9.4GB.

DVD-R - Stands for "Digital Versatile Disc Recordable." A DVD-R looks the same as a regular DVD, but like a CD-R, it can be used to record data. Once a DVD-R has been "burned," or written to, it cannot be written to again. A basic single-sided, single-layer DVD-R disc can store 4.7GB of data. Double-layer discs can store 8.5GB, while double-sided DVD-Rs can store 9.4GB. DVD-R is the most common format of writable DVDs.

DVD-RAM - Stands for "Digital Versatile Disc Random Access Memory." DVD-RAMs are writable DVDs that can be erased and rewritten like DVD-RW and DVD+RW discs. Unlike the other two writable DVD formats, DVD-RAM discs support advanced error correction and defect management. While these features slow down the maximum data transfer rate for DVD-RAM discs, it also makes the discs more reliable.

DVI - Stands for "Digital Video Interface." DVI is a video connection standard created by the Digital Display Working Group (DDWG). Most DVI ports support both analog and digital displays.

DVR - Stands for "Digital Video Recorder." A DVR is basically a VCR that uses a hard drive instead of video tapes. It can be used to record, save, and play back television programs. Unlike a VCR, however, a DVR can also pause live TV by recording the current show in real time. The user can choose to fast forward (often during commercials) to return to live television.

E

E-commerce - E-commerce (electronic-commerce) refers to business over the Internet.

ECC - Stands for "Error Correction Code." ECC is used to verify data transmissions by locating and correcting transmission errors. It is commonly used by RAM chips that include forward error correction (FEC), which ensures all the data being sent to and from the RAM is transmitted correctly.

EIDE - Stands for "Enhanced Integrated Drive Electronics." EIDE is an improved version of the IDE drive interface that provides faster data transfer rates than the original standard. While the original IDE drive controllers supported transfer rates of 8.3 Mbps, EIDE can transfer data up to 16.6 Mbps, which is twice as fast.

Exabyte - An exabyte is 2 to the 60th power, or 1,152,921,504,606,846,976 bytes. It can be estimated as 10 to the 18th power, or 1,000,000,000,000,000,000 bytes. An exabyte is 1,024 petabytes and precedes the zettabyte unit of measurement. While a 64-bit processor can theoretically use 16 exabytes of address space, exabytes are so large, the units are rarely used in a practical context.

Executable - An executable file is a type of computer file that runs a program when it is opened. This means it executes code or a series of instructions contained in the file. The two primary types of executable files are 1) compiled programs and 2) scripts. On Windows systems, compiled programs have an .EXE file extension and are often referred to as "EXE files." On Macintosh computers, compiled programs have an .APP extension, which is short for application.

F

FAT32 - This strange term refers to the way Windows stores data on your hard drive. "FAT" stands for "File Allocation Table," which keeps track of all your files and helps the computer locate them on the disk.

FIFO - Stands for "First In, First Out." FIFO is a method of processing and retrieving data. In a FIFO system, the first items entered are the first ones to be removed. In other words, the items are removed in the same order they are entered.

FiOS - Stands for "Fiber Optic Service." FiOS is a data communications service provided by Verizon that uses fiber optic cables to transfer data. FiOS is called a "Fiber to the Premises," or FTTP service, since it brings fiber optic data transmission to residential homes as well as businesses. Since fiber optic technology sends data via pulses of light, it is the fastest method of transferring data.

Firewire - This high-speed interface has become a hot new standard for connecting peripherals (no pun intended). Firewire can be used to connect devices such as digital video cameras, hard drives, audio interfaces, and MP3 players, such as the Apple iPod, to your computer. A standard Firewire connection can transfer data at 400 Mbps, which is roughly 30 times faster than USB 1.1. This blazing speed allows for quick transfers of large video files, which is great for video-editing professionals. If 400 Mbps is still not fast enough, Apple Computer released new PowerMacs with Firewire 800 ports in early 2003. These ports support data transfer rates of 800 Mbps - twice the speed of the original Firewire standard.

Firmware - Firmware is a software program or set of instructions programmed on a hardware device. It provides the necessary instructions for how the device communicates with the other computer hardware.

Flash Drive - lash drives have many names — jump drives, thumb drives, pen drives, and USB keychain drives. Regardless of what you call them, they all refer to the same thing, which is a small data storage device that uses flash memory and has a built-in USB connection.

Floppy Disk - Floppy disks have an interesting name, considering they do not appear to be "floppy." However, if you take the actual disk out of the protective casing, you will discover that the disk is, in fact, rather flexible. It is coated with iron oxide and stores data magnetically, just like a hard disk.

FLOPS - Stands for "Floating Point Operations Per Second." FLOPS are typically used to measure the performance of a computer's processor. While clock speed, which is measured in megahertz, is often seen as an indicator or a processor's speed, it does not define how many calculations a processor can perform per second. Therefore, FLOPS is a more raw method of measuring a processor's processing speed.

FPU - Stands for "Floating Point Unit." The first computer processors were far better at dealing with integers than with real numbers (a.k.a. floating point numbers). So a separate FPU processor was developed to handle the floating point calculations.

FTP - Stands for "File Transfer Protocol." It is a common method of transferring files via the Internet from one computer to another.

G

Gbps - Stands for "Gigabits per second." 1Gbps is equal to 1,000 Megabits per second (Mbps), or 1,000,000,000 bits per second. Gbps is commonly used to measure data transfer speeds between hardware devices.

Gigabyte - A gigabyte is 2 to the 30th power, or 1,073,741,824 bytes.

Gigaflops - Gigaflops is a unit of measurement used to measure the performance of a computer's floating point unit, commonly referred to as the FPU. One gigaflops is one billion (1,000,000,000) FLOPS, or floating point operations, per second.

Gigahertz - One gigahertz is equal to 1,000 megahertz (MHz) or 1,000,000,000 Hz. It is commonly used to measure computer processing speeds.

GPS - Stands for "Global Positioning System." GPS is a satellite navigation system used to determine ground position and velocity (location, speed, and direction).

GPU - Stands for "Graphics Processing Unit." Like the CPU (Central Processing Unit), it is a single-chip processor. However, the GPU is used primarily for computing 3D functions. This includes things such as lighting effects, object transformations, and 3D motion. Because these types of calculations are rather taxing on the CPU, the GPU can help the computer run more effienciently.

GUI - Stands for "Graphical User Interface," and is pronounced "gooey." It refers to the graphical interface of a computer that allows users to click and drag objects with a mouse instead of entering text at a command line.

H

Hard Disk / Drive - When you save data or install programs on your computer, the information is typically written to your hard disk. The hard disk is a spindle of magnetic disks, called platters, that record and store information.

Hardware - Computer hardware refers to the physical parts of a computer and related devices. Internal hardware devices include motherboards, hard drives, and RAM. External hardware devices include monitors, keyboards, mice, printers, and scanners.

HDMI - Stands for "High-Definition Multimedia Interface." HDMI is a digital interface for transmitting audio and video data in a single cable. It is supported by most HDTVs and related components, such as DVD and Blu-ray players, cable boxes, and video game systems.

HDTV - Stands for "High Definition Televsion." HDTV is a high-quality video standard developed to replace older video formats often referred to as SDTV (standard definition television). While HDTV's video quality is one of the most noticeable improvements over SDTV, HDTV includes a number of other important improvements as well.

Heat Sink - A computer's CPU may perform millions of calculations every second. As the processor continues to work at a rapid pace, it begins to generate heat. If this heat is not kept in check, the processor could overheat and eventually destroy itself.

Hexadecimal - Hexadecimal is a base-16 number system. It is a different method of representing numbers than the base-10 system we use in every day practice. In base-10, we count in multiples of 10 before adding another digit. For example, "8 - 9 - 10 - 11 - 12..." and "98 - 99 - 100 - 101 - 102..." Notice how a new digit is added when the number 10 is reached, and another digit is added to represent 100 (10x10). In base-16, or the hexadecimal number system, each digit can have sixteen values instead of ten.

HFS - Stands for "Hierarchical File System." HFS is the file system used for organizing files on a Macintosh hard disk. When a hard disk is formatted for a Macintosh computer, the hierarchical file system is used to create a directory that can expand as new files and folders are added to the disk.

HSF - Stands for "Heat Sink and Fan." Nearly all computers have heat sinks, which help keep the CPU cool and prevent it from overheating.

HTML - Stands for "Hyper-Text Markup Language." This is the language that Web pages are written in. Also known as hypertext documents, Web pages must conform to the rules of HTML in order to be displayed correctly in a Web browser. The HTML syntax is based on a list of tags that describe the page's format and what is displayed on the Web page.

HTTP - Stands for "HyperText Transfer Protocol." This is the protocol used to transfer data over the World Wide Web. That's why all Web site addresses begin with "http://". Whenever you type a URL into your browser and hit Enter, your computer sends an HTTP request to the appropriate Web server. The Web server, which is designed to handle HTTP requests, then sends to you the requested HTML page.

HTTPS - Stands for "HyperText Transport Protocol Secure." HTTPS is the same thing as HTTP, but uses a secure socket layer (SSL) for security purposes. Some examples of sites that use HTTPS include banking and investment websites, e-commerce websites, and most websites that require you to log in.

Hyper-Threading - Hyper-threading is a technology developed by Intel Corporation. It is used in certain Pentium 4 processors and all Intel Xeon processors. Hyper-threading technology, commonly referred to as "HT Technology," enables the processor to execute two threads, or sets of instructions, at the same time. Since hyper-threading allows two streams to be executed in parallel, it is almost like having two separate processors working together.

I

I/O - Stands for "Input/Output" and is pronounced simply "eye-oh." Computers are based on the fundamental idea that every input results in an output.

ICMP - Stands for "Internet Control Message Protocol." When information is transferred over the Internet, computer systems send and receive data using the TCP/IP protocol. If there is a problem with the connection, error and status messages regarding the connection are sent using ICMP, which is part of the Internet protocol.

ICS - Stands for "Internet Connection Sharing." ICS allows multiple computers to connect to the Internet using the same Internet connection and IP address.

IDE - IDE is one of the most widely-used hard drive interfaces on the market. The fancy name refers to how the technology integrates the electronics controller into the drive itself. While the original IDE standard could only support hard drives containing up to 540 MB of data, the new standard, EIDE (Enhanced-IDE), supports hard drives with over 250 GB of data. It also allows for data transfer rates that are over twice as fast as the original IDE.

Integrated Circuit - An integrated circuit, or IC, is small chip that can function as an amplifier, oscillator, timer, microprocessor, or even computer memory. An IC is a small wafer, usually made of silicon, that can hold anywhere from hundreds to millions of transistors, resistors, and capacitors. These extremely small electronics can perform calculations and store data using either digital or analog technology.

InterNIC - Stands for "Internet Network Information Center." The InterNIC is an organization created by the National Science Foundation to provide Internet information and domain name registration services. While the InterNIC was started as a joint effort between Network Solutions and AT&T, it is now run by the Internet Corporation For Assigned Names and Numbers (ICANN).

Intranet - Contrary to popular belief, this is not simply a misspelling of "Internet." "Intra" means "internal" or "within," so an Intranet is an internal or private network that can only be accessed within the confines of a company, university, or organization. "Inter" means "between or among," hence the difference between the Internet and an Intranet.

IP - Stands for "Internet Protocol." It provides a standard set of rules for sending and receiving data through the Internet.

IP Address - Also known as an "IP number" or simply an "IP," this is a code made up of numbers separated by three dots that identifies a particular computer on the Internet. Every computer, whether it be a Web server or the computer you're using right now, requires an IP address to connect to the Internet. IP addresses consist of four sets of numbers from 0 to 255, separated by three dots. For example "66.72.98.236" or "216.239.115.148".

IPv4 - IPv4 is the most widely used version of the Internet Protocol. It defines IP addresses in a 32-bit format, which looks like 123.123.123.123. Each three-digit section can include a number from 0 to 255, which means the total number of IPv4 addresses available is 4,294,967,296 (256 x 256 x 256 x 256 or 2^32).

IPv6 - IPv6, also called IPng (or IP Next Generation), is the next planned version of the IP address system. (IPv5 was an experimental version used primarily for streaming data.) While IPv4 uses 32-bit addresses, IPv6 uses 128-bit addresses, which increases the number of possible addresses by an exponential amount. For example, IPv4 allows 4,294,967,296 addresses to be used (2^32). IPv6 allows for over 340,000,000,000,000,000,000,000,000,000,000,000,000 IP addresses. That should be enough to last awhile.

IRQ - Stands for "Interrupt Request." PCs use interrupt requests to manage various hardware operations. Devices such as sound cards, modems, and keyboards can all send interrupt requests to the processor.

ISA - Stands for "Industry Standard Architecture." ISA is a type of bus used in PCs for adding expansion cards. For example, an ISA slot may be used to add a video card, a network card, or an extra serial port. The original 8-bit version of PCI uses a 62 pin connection and supports clock speeds of 8 and 33 MHz. 16-bit PCI uses 98 pins and supports the same clock speeds.

J

Jumper - his is a small metal connector that acts as an on/off switch and is used to alter hardware configurations. A jumper is typically made of two wires and a small piece of metal. When the wires are connected by the metal piece, the jumper is turned on, completing the circuit. When the wires are disconnected, the jumper is turned off. Mulitple jumpers, referred to collectively as a jumper block, are often used to tell the computer how a certain device, such as a hard drive or a modem, is configured.

K

KVM Switch - Stands for "Keyboard, Video, and Mouse switch." As the name implies, a KVM switch allows you to used multiple computers with the same keyboard, video display, and mouse. Now, most of us don't need to use two computers at once. In fact, using one computer at a time can sometimes be a challenge. However, there are situations where using a single keyboard, mouse, and display with multiple machines can be very practical.

L

LAN - Stands for "Local Area Network". A LAN is a computer network limited to a small area such as an office building, university, or even a residential home.

Latency - This is the amount of time it takes a packet of data to move across a network connection. When a packet is being sent, there is "latent" time, when the computer that sent the packet waits for confirmation that the packet has been received. Latency and bandwidth are the two factors that determine your network connection speed.

LCD - Stands for "Liquid Crystal Display." LCDs are super-thin displays that are used in laptop computer screens and flat panel monitors. Smaller LCDs are used in handheld TVs, PDAs, and portable video game devices.

LED - Stands for "Light-Emitting Diode." An LED is an electronic device that emits light when an electrical current is passed through it. Early LEDs produced only red light, but modern LEDs can produce several different colors, including red, green, and blue (RGB) light.

LIFO - Stands for "Last In, First Out." LIFO is a method of processing data in which the last items entered are the first to be removed. This is the opposite of LIFO is FIFO (First In, First Out), in which items are removed in the order they have been entered.

Localhost - "Localhost" refers to the local computer that a program is running on. For example, if you are running a Web browser on your computer, your computer is considered to be the "localhost." While this does not need to be specified when using a single computer, the localhost does need to be defined when running programs from multiple computers.

M

MAC Address - Stands for "Media Access Control Address," and no, it is not related Apple Macintosh computers. A MAC address is a hardware identification number that uniquely identifies each device on a network. The MAC address is manufactured into every network card, such as an Ethernet card or Wi-Fi card, and therefore cannot be changed.

Malware - Short for "malicious software," malware refers to software programs designed to damage or do other unwanted actions on a computer system. Common examples of malware include viruses, worms, trojan horses, and spyware. Viruses, for example, can cause havoc on a computer's hard drive by deleting files or directory information. Spyware can gather data from a user's system without the user knowing it. This can include anything from the Web pages a user visits to personal information, such as credit card numbers.

Mbps - Stands for "Megabits Per Second." One megabit is equal to one million bits or 1,000 kilobits. While "megabit" sounds similar to "megabyte," a megabit is roughly one eighth the size of a megabyte (since there are eight bits in a byte).

Megabyte - A megabyte is 2 to the 20th power, or 1,048,576 bytes.

Memory - While memory can refer to any medium of data storage, it usually refers to RAM, or random access memory. When your computer boots up, it loads the operating system into its memory, or RAM. This allows your computer to access system functions, such as handling mouse clicks and keystrokes, since the event handlers are all loaded into RAM. Whenever you open a program, the interface and functions used by that program are also loaded into RAM.

Metadata - Metadata describes other data. It provides information about a certain item's content. For example, an image may include metadata that describes how large the picture is, the color depth, the image resolution, when the image was created, and other data. A text document's metadata may contain information about how long the document is, who the author is, when the document was written, and a short summary of the document.

Motherboard - The motherboard is the main circuit board of your computer and is also known as the mainboard or logic board. If you ever open your computer, the biggest piece of silicon you see is the motherboard. Attached to the motherboard, you'll find the CPU, ROM, memory RAM expansion slots, PCI slots, and USB ports. It also includes controllers for devices like the hard drive, DVD drive, keyboard, and mouse. Basically, the motherboard is what makes everything in your computer work together.

Multi-Core - Multi-core technology refers to CPUs that contain two or more processing cores. These cores operate as separate processors within a single chip. By using multiple cores, processor manufacturers can increase the performance of a CPU without raising the processor clock speed. Since the upper threshold of clock speeds has leveled out during recent years, multi-core processors have become a common means to improve computing performance.

Multithreading - Multithreading is similar to multitasking, but enables the processing of multiple threads at one time, rather than multiple processes. Since threads are smaller, more basic instructions than processes, multithreading may occur within processes.