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| Bit | A bit is the most basic unit of information on a computer, comprised of either a 1 or a 0. All other information stored on or used by the computer is comprised of combinations of bits. |
| Byte | A combination of 8 bits. One byte represents a single letter, symbol, or number between 0 and 9. Hard disk capacity, floppy disk capacity, and RAM memory are measured in thousands of bytes (kilobytes), millions of bytes (megabytes), or billion of bytes (gigabytes). |
| CD-ROM (compact disk- read only memory) | A storage device that stores typically holds approximately 660 MB of computer software. |
| CPU (Central Processing Unit) | Another name given to a computer. CPU usually denotes the box which contains the microprocessor, power supply, hard drive, and disk drives. |
| Diskette | Diskettes are convenient, portable storage devices. The most commonly used diskettes in the early phases of microcomputer use were 5 1/4 inches in diameter and were "floppy," that is they were stored in a lightweight, flexible plastic envelopes. They typically stored 750K of software of files. The most common disks currently are 3 1/2 inches in diameter and are stored in a rigid plastic case. The amount of software or files that can be stored on a disk is still limited - 2 MB is the maximum storage on most disks. In order to access the information stored on a diskette, the diskette must be placed in the computer's disk drive (sometimes called a floppy disk drive). |
| Hand Held Device | Hand held devices are small microcomputers that can be held in your hand. The most common uses include electronic dictionaries, calculators, language translators, and image scanners. |
| Hard Drive | A device which stores large amounts of computer information on a semipermanent basis. |
| Internet | The Internet is the largest computer network in the world. Computers on the Internet have two things in common. First, all of the computers are connected to one another on a round-the-clock basis. Second, all of the computers use a common "language," the Transmission Control Protocol/Internet Protocol (TCP/IP), to communicate with one another. Services like AOL, Delphi Internet Services, and others provide their members with access to some or all of the information resources on the Internet, but the user’s computer is not on the Internet per se because it does remain connected twenty four hours-a-day. The Internet provides software and document retrieval, electronic mail, bulletin boards and other services to users. |
| Keyboard | An input device that allows users to provide the computer with new information or directions for operation through a typewriter-like series of keys. |
| Light Pen | A light pen is an input device. Light pens typically have a cable that attaches them to the computer. The user touches the screen with the light pen to indicate a response. |
| Local Area Network (LAN) | Two or more microcomputers linked together via a system of cables and specialized software. LANs are usually confined to one building. All the computers linked in a LAN can access the same library of software. |
| Microcomputer | A type of computer that superseded the large mainframes developed during the 1960s and 1970s. Microcomputers use microprocessors to control the computer's actions and to perform all computation rather than vacuum tubes. |
| Modem | A piece of equipment that connects a computer to a data transmission line (typically a telephone line of some sort). Modems allow tow computers to exchange data with one another. |
| Monitor | A device that is connected to a computer and used to display text and graphics. Monitors are similar to regular TV sets, but use a digital signal rather than an analog signal like the TV. |
| Mouse | The mouse is a much more sophisticated and flexible pointing device than the arrow keys on the keyboard. It allows one to move the cursor to any point on the screen very quickly and only takes about ten minutes of practice to master. |
| Network | Two or more computers connected electronically so that people using them can share files and devices (such as printers and modems) and exchange electronic mail. |
| Printer | An output device used to create text and graphic images on paper. Printers come in three types: Laser printers produce the highest quality output and highest printing speed, but are generally more expensive than ink jets and dot matrix printers. Ink jet printers use a stream of tiny ink dots to create images on paper. Because the ink does not dry immediately, the images tends to smudge and blur. However, ink jet printers are substantially cheaper and can produce high quality output if used carefully. Dot matrix printers create images by tapping tiny pins against a ribbon as the cartridge moves across the page. Dot matrix printers are slower and produce output generally considered unsuitable for professional purposes. Dot matrix printers are usually cheaper than ink jet printers. |
| RAM (Random Access Memory) | RAM is memory the computer uses to temporarily store information that the microprocessor needs to operate a computer program. Information stored in RAM is lost the moment power is interrupted to the computer. The amount of RAM determines the size of programs that can be executed by the computer. |
| ROM (Read Only Memory) | ROM stores special instructions that the computer needs in order to run properly. As the name implies, information stored in ROM is never changed, only read as needed. |
| Scanner | A device that converts a printed page into an electronic representation that can be viewed and manipulated on the computer. Scanners are often used to convert photographs into electronic representations so that they can be included in documents created on the computer. |
| Touch Screen | The touch screen allows the user to input information by actually touching the screen of the computer's monitor. Sometimes an electronic device called a light pen is used to touch the screen, but often one just uses his/her finger or the eraser on a pencil. |
| Virus | A destructive type of computer program that attempts to interfere with the normal operation of the computer, re-write or delete information from hard drives or floppy disks, and, in some cases, cause physical damage to the computer. Viruses are usually developed by programmers to demonstrate their technical expertise and often are not intended to cause the harm done. Viruses can be spread from computer to computer over networks and by sharing floppy disks. Several free and commercial software packages are available which can detect and remove viruses already on a computer; these packages can also prevent infection by continuously monitoring the computer for signs of infection. |
| Wide Area Networks | (I.e., Internet, America On Line, etc.) - A network that spans many geographically separated locations. WAN links local networks or individuals users through a special type of telephone line provided by a telecommunications service, such as a leased line or fiber optic cable. |
