Glossary of Computing and Automation Terms

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

ActiveX
Microsoft's toolkit for Web developers, using OLE and incorporating Sun's Java language. ActiveX helps in building software to integrate with Microsoft's Internet Explorer, or any ActiveX container such as programs written with Microsoft's Visual Studio.

Address
The value that represents an individually accessible storage location. In a typical computer or PLC, each memory location has a separate address.

Alphanumeric
Consisting of numbers and letters.

American National Standards Institute (ANSI)
ANSI promotes standards for the American computer industry and coordinates American involvement in the International Standards Organization.

Analog
Just as pairs of things are said to be analogs if they exhibit similar features and behavior, an analog device uses convenient physical quantities or properties to represent other physical quantities; for example, a variation in the electric current in a wire can represent an audible sound and this can be translated back into sound by a speaker unit (say in the part of a telephone handset placed on the ear). Likewise, an electric voltage or the position of a point on a dial might represent the speed of a motor or the temperature of a furnace. This contrasts with digital devices, which use numbers (or digits) to represent physical quantities.

Application Programming Interface (API)
A set of software functions or specifications supplied by a vendor to facilitate exchanges of data with third party software or hardware.

Artificial Intelligence (AI)
A set of principles and associated methods that tries to mimic natural (living world) intelligence. Two extremely different approaches have yielded useful results: Rule-Based AI (as used in Expert Systems) and Neural Nets.

ASCII - acronym for American Standard Code for Information Interchange.
A coding scheme that assigns numeric values to letters, numbers, punctuation marks, and certain other characters. By standardizing the values used for these characters, ASCII enables computers and computer programs to exchange information.

ASDL
Asymmetric Digital Subscriber Line allows for transfer speeds of 9 Megabytes per second into the computer and up to 800 kbps back up the telephone lines. ADSL uses standard telephone lines, but presently require the user to install a separate telephone line. ADSL is just entering the consumer market in a few areas. Several large companies (including Alcatel, Cisco, Microsoft and USRobotics) are working together on a standard that will include simultaneous voice and data transmission.

Asynchronous Operation
Generally, an operation that proceeds independently of any timing mechanism, such as a clock. In communications, for example, two modems communicating asynchronously rely upon each sending the other start and stop signals in order to pace the exchange of information.

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B

Backbone
In networks or telecommunications, the main cable or channel.

Bandwidth
In communications, the difference between the highest and lowest frequencies in a given range. In computer networks, greater bandwidth indicates faster data-transfer capability.

Bar Code
A series of horizontal stripes or bars of varying width which represent a string of characters that can be read by a bar code reader.

Batch Processing
Running accumulated data through a program off-line, without user intervention. Used where very large volumes of data require similar processing. For example, in clearing banks, records of each day's transactions are accumulated at branches for subsequent mass batch processing by the central computer.

Baud Rate
Commonly, a reference to the speed at which a modem can transmit data. Often incorrectly assumed to indicate the number of bits per second (bps) transmitted, baud rate actually measures the number of events, or signal changes, that occur in 1 second. Because one event can actually encode more than 1 bit in high-speed digital communications, baud rate and bits per second are not always synonymous, and the latter is the more accurate term to apply to modems. For example, a so-called 9600-baud modem that encodes 4 bits per event actually operates at 2400 baud but transmits 9600 bps modem.

Bill of Materials (BOM)
A list of components, ingredients, or materials needed to manufacture a product; the hierarchy of materials or components making up a product or subassembly including the proper ratios of quantities of each item.

Binary
Having only two possible states or values: e.g. either true or false, open or closed, 0 or 1.

BIOS
Acronym for basic input/output system, a set of routines that work closely with the hardware to support the transfer of information between elements of the system, such as memory, disks, and the monitor. On IBM and compatible computers, the BIOS, or ROM BIOS, is built into the machine's read-only memory (ROM). Although critical to performance, the BIOS is usually invisible to computer users. The BIOS can, however, be accessed by programmers.

bit
Short for binary digit; either 1 or 0 in the binary number system. In processing and storage, a bit is the smallest unit of information handled by a computer. Considered singly, bits convey little information a human would consider meaningful. In groups of eight, however, bits become the familiar bytes used to represent all types of information, including the letters of the alphabet and the digits 0 through 9.

bitmap
An image stored pixel by pixel, with every pixel represented individually in the memory or storage device. The term 'bitmap' is used because it is possible for the state ('on' or 'off') of a single bit to represent the state of a corresponding pixel, just as a point on the surface of an ordinary map represents a corresponding point in the piece of country concerned. Because graphics generally contain a large number of pixels, each of which has not only position but color and intensity, bitmap storage uses a large amount of memory or disk space. However, unlike Vector graphics it needs no mathematical calculations to generate images, and is preferred for images of subtlety and detail. Also, bitmap is the only practical way of storing scanned-in digitized graphics.

browser
On the Internet a suite of programs that allows both viewing and navigation from one node (or address) on the Internet to another. Examples of browsers are Mosaic, Netscape and Tapestry. All browsers act as clients to the remote servers.

byte
A unit if information consisting of 8 bits; in computer processing and storage, the equivalent of a single character, such as a letter, a numeral, or a punctuation mark. Because a byte represents only a small amount of information, amounts of computer memory and storage are usually given in kilobytes (1024 bytes) or megabytes (1,048,576 bytes).

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C

cache
A special memory subsystem in which frequently used data values are duplicated for quick access. A memory cache stores the contents of frequently accessed RAM locations and the addresses where these data items are stored. A cache is useful when RAM accesses are slow compared with the microprocessor speed because cache memory is always faster than main RAM memory.

CAD (Computer Aided Design)
Programs used to design architectural and mechanical engineering drawings.

CAM (Computer Aided Manufacturing)
Programs used to control manufacturing equipment.

CASE
Computer Aided Software Engineering. A Development Environment providing facilities for drawing diagrams that represent the logic and processes of systems, plus a Database (called a Data Dictionary describing the types of data). Some CASE packages include code generation facilities, so that once a system has been specified, much of the programming can be produced automatically.

CD-ROM (Compact Disc Read-Only Memory)
A compact disc containing data that can be read by a computer; characterized by high capacity (roughly 600 megabytes) and the use of laser optics rather than magnetic means for reading data; information on a CD-ROM cannot be changed or altered. CD-ROM drive A disk storage device that uses compact disc technology.

Central Processing Unit (CPU)
The computational and control unit of a computer; the device that interprets and executes instructions. The CPU has the ability to fetch, decode, and execute instructions and to transfer information to and from other resources over the computer's main data-transfer path, the bus.

character set
A collection of characters, e.g. A to Z, 0 to 9, punctuation marks, mathematical symbols, graphics and others. Each character in a set is represented by a binary value (sometimes called a bit pattern). Different character sets have different binary values for characters. Examples of character sets are ASCII, EBCDIC And Kangi.

client
Any intelligent device linked in a network to a server. A client can undertake its own computing using data provided by the server.

client/server
A system in which a number of 'client' devices (usually PCs or workstations) are connected via a network to one or more data storage and retrieval machines known as 'servers'. When a user runs a program, their machine (the client) passes any requests for data (along with selection criteria and sorting instructions) to servers. Servers generally hold information in a database format, and should be capable of filtering out the required elements, putting them in order as instructed by their clients, and thus sending just the necessary amount of information back across the network. When the client machine receives the requested information, it processes it according to software held in its own memory. Another useful but more technical description of client/server is 'running software' in parallel on multiple nodes (many PCs operating at the same time on one Network), whereas mainframes and minis run software on one node only (the host machine). Client/server architecture is being increasingly adopted as a means of maximizing the effectiveness of multi-user systems where a number of different applications need to be running simultaneously. In control and telecommunications systems, the term used instead of 'client/server' is 'distributed processing'.

Common Object Request Broker Architecture (CORBA)
A standard from the Object Management Group (OMG), providing interface definitions and protocols between objects. Competes with OLE from Microsoft. communications server In networks, a dedicated system that manages communications activities for other computers.

compiler
A program that converts source code to object code which can be linked to produce an executable program.

Computer Integrated Manufacturing (CIM)
A term used for describing a high level of automation in a manufacturing enterprise.

cyberspace
An Internet term meaning the virtual universe of communication without physical presence within the Internet.

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D

data acquistion
A term commonly used for equipment or software that gathers data from devices through a communcations channel.

database
A user defined table that is bound to an operation and is used to store process or product data.

data mining
Analysis of data in a Database using tools which look for trends or anomalies (irregularities).

data structure
The way data is organized, its field attributes and its relationships to other data in databases, tables and files.

data transfer rate
The speed of the movement of information from one location to another.

database server
A server that holds and manages a database of information in a client/server network.

delimiter
A character that defines the start and end of field, but is not part of that field. Commas are often used, as in comma-separated files (.CSV files).

device driver
A software component that permits a computer system to communicate with a device. A printer driver is a device driver that translates computer data into a form understood by the intended printer.

Dual In-Line Package (DIP)
The plastic or ceramic carrier device that houses a chip or other electrical devices.

dynamic link library (DLL)
A software module loaded into memory at execution time in order to access functions of that module.

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E

EISA (Extended Industry Standard Architecture) bus
A bus that extends an 8-bit or 16-bit bus design to 32 bits.

emulate
To copy the way something else works. In computing, different operating system environments make it difficult or impossible to move software around. This is handled to some degree by writing new software for the different operating system which copies the functions of original software.

encrypt
Code or format data to make it hard for unauthorized persons to understand it; as in encryption.

encryption
Encoding information, often in communications, so that only the proper recipient can understand the message by decoding it. Examples of Encryption are PGP and RSA.

Erasable Programmable Read Only Memory (EPROM)
This sounds like a contradiction in terms as ROMs are Read only Memory that by definition cannot be erased by switching off the current. However, EPROM acts as ROM unless special action is taken. An EPROM contains charge in a transistor gate that holds it for up to 10 years. Applying ultraviolet light to the chip's surface dissipates the charge, erasing the memory content and allowing the reprogramming of the chip through the transistor gate using a higher voltage than is normally present on a PC board.

ethernet
A LAN Transmission standard. It is a high speed, CSMA/CD baseband network that runs over Thin Wire, Thick Wire, twisted-pair or fiber optic cable.

Extremely Low Frequency (ELF)
The frequency range is defined from 30 to 300Hz. ELF's have been associated with a variety of health effects, both in laboratory experiments and epidemiological surveys.

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F

fault tolerant
Able to withstand a considerable degree of error without crashing. This may involve copying data or mirroring data and having extra capacity. It is often achieved by using several separate processors, each monitoring the others and operating a voting system, so that if one fails, the others shut it down, call for human help and carry on operations.

File Allocation Table (FAT)
A table or list maintained by some operating systems to keep track of the status of various segments of disk space used for file storage. It enables the operating system to maintain a map of available disk storage space so that it can mark flawed segments that should not be used and can find and link the pieces of a file.

file server
A computer that holds data for network users.

firewall
A protective system of coding that isolates sensitive parts of a system or confidential areas from users who do not have the authority (passwords) for access.

flow chart
In software development, a visual representation of the flow of data through the various entities of a system.

font
Traditionally, a set of characters of the same typeface (such as Courier), style (such as italic), stroke weight (such as bold) and size. A font is not to be confused with a typeface. Font is a specific size of a specific typeface, such as 12-point Helvetica or 10-point Times Roman. Typeface refers to the design itself.

frequency
Defines number of events during a time period. Hertz (Hz) is a measurement of frequency.

Frequently Asked Questions (FAQ)
A list of commonly asked questions and answers on a particular subject and their answers.

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G

gigabyte (GB)
The precise meaning of this word often varies with the context; strictly, a gigabyte is 1 billion bytes. In reference to computers, however, bytes are often expressed in multiples of two. Therefore, a gigabyte can also be either 1000 megabytes, 1024 megabytes or 1,073,741,824 bytes.

Good Manufacturing Practices (GMP)
A methodology of specification for a manufacturing process that ensures quality, safety, and engineering tolerances are met.

graphical user interface (GUI)
A type of display format that enables the user to choose commands, start programs, and see lists of files and other options by pointing to pictorial representations (icons) and lists of menu items on the screen. Choices can generally be activated either with the keyboard or with a mouse.

grounding
The intentional connection of sections of an electrical circuit to a common reference conductor called the ground. The ground is almost always at a potential of zero volts and serves as the reference for the other voltages in the circuit.

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H

hertz (Hz.)
A unit of measurement that measures how often a periodic event, such as a waveform, occurs. One hertz equals one cycle per second. Frequency is often measured in kilohertz (KHs, 1000Hz), megahertz (MHz, 1000 KHz), gigahertz (GHz, 1000MHz), or terahertz (THz, 1000 GHz).

hexadecimal (hex)
Numerical system based on 16 rather than the 10 in the decimal system or 2 in binary. The numbering starts at 1, goes to 9, then A B C D E F (F=15).After 'F', '10' would then be the first double digit number, and represents the decimal value 16. For programmers, the hexadecimal system makes it more convenient to handle the large binary numbers encountered in computer systems.

HTML
On the Internet, Hypertext Markup Language, a Language used to write a 'page' for display. The language is simple and provides only 'format' and 'go to' -type features.

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I

I/O port
A channel through which data is transferred between an input or output device and the microprocessor. The port appears to the CPU as one or more memory addresses that it can use to send or receive data.

Industry Standard Architecture (ISA)
An unofficial designation for he bus design of the IBM PC/XT, which allows various adapters to be added to the system by means of inserting plug-in cards into expansion slots.

Institute of Electrical and Electronics Engineers (IEEE)
An organization of engineering and electronics professionals notable for developing the IEEE 802 standards for the physical and data-link layers of local area networks following the ISO Open Systems Interconnection model.

instruction set
A set of Microcode particular to one type of chip, (such as HP's PA RISC chip or Intel's iAPX86 CISC chip).

integer
A whole number. In PCs and PLCs, it is represented with a 16 or 32 bit number, with one bit devoted to sign for negative values. A 16 bit number can represent 0 to 65535 (-32768 to 32767 with sign). A 32 Bit number can represent 0 to 4,294,967,295 (-2,147,483,648 to 2,147,483,647 with sign)

integrated circuit
A collection of electronic devices working together.

integrator
An application builder; an application programmer who customizes a program by enhancing and building user interfaces so programs can communicate and share data.

Internet
The collection of networks and gateways that use the TCP/IP protocols.

Internet Service Provider (ISP)
A company providing connectivity to the Internet in terms of user connections, the relevant Internet address and related software, and Home Pages for those who wish to put information on the Web.

Intranet
Corporate multi-user systems using Internet technology, often based on free software. This is a low-cost option for organizations wanting a Global Network.

IP address
The network address on a TCP/IP Network, represented as X.X.X.X, where each X=0 to 255. Provides 4 Billion possible network addresses.

ISO 9000
A set of standards authored by the Geneva-based International Standards Organization (ISO) which defines the basic ingredients of a quality system for manufacturing, including documentation controls and training. Certification is granted to individual facilities, not specific products (Chan/Levin/Humes, 1993).

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J

java
A language authored by Sun, used for Internet software development to create client/server applications. Java can create 'applets' that can be downloaded over the Internet to the user's PC which will immediately run.

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K

kilobyte (KB)
A unit of measure. One kilobyte contains 1,024 bytes.

kilohertz (KHz)
A measurement of frequency equivalent to 1000 hertz, or 1000 cycles per second. (Also see "hertz".)

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L

latency
The delay time between the end of one communication and the start of another. During this time, the processes associated with the communication are hung up and cannot continue. Software engineers work to reduce latency to a minimum.

Linux
Version of UNIX freeware available on the Internet. Linux was developed in 1991 by Linus Torvalds.

Local Area Network (LAN)
A network physically confined to a small region of space, typically within a single building; contrasting with a

log
A record of transactions or activities that take place on a computer system.

logic
In programming, the assertions, assumptions and operations that define what a given program does. Defining the logic of a program is often the first step in developing the program's source code.

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M

magnetically shielded
The magnets on a device are protected to prevent interference with other devices, such as a monitor.

Manufacturing Execution Systems (MES)
A type of software application that provides tools for modeling or defining the various operations or steps in the process as well as resources such as machines and labor. MES tracks products through a manufacturing process, provides dynamic dispatching, engineering document management, and data collection. MES maintains a complete record of the manufacturing process, including product geneology and traceability.

Material Resource Planning (MRP)
A software system of applications that provides services to manange order entry, order processing, and maintenance, financials, inventory management, activity based costing, work order management, scheduling, and other similiar functions.

Mean Time Between Failure (MTBF)
A statistically derived measure of the probable time a device will operate before a hardware failure occurs.

megabyte (MB)
A unit of measurement of memory. One megabyte is 1,048,476 bytes.

megahertz (MHz)
A measure of frequency equivalent to 1 million cycles per second.

memory
Circuitry that allows information to be stored and retrieved. In the most general sense, memory can refer to external systems such as disk drives or tape drives; in common usage, it refers only to the fast semiconductor storage (RAM) directly connected to the processor.

microprocessor
A central processing unit (CPU) on a single chip. Microprocessors are at the heart of all personal computers. When memory and power are added to a microprocessor, all the pieces excluding peripherals required for a computer are present.

Millions of Instructions Per Second (MPS)
A measure of the speed of a computer. Unfortunately, each manufacturer uses the interpretation of this Benchmark which favors his own product, making it difficult to assess the true performance of his machine.

modem (MOdulate/DEModulate)
A communications driver that enables a computer to transmit information over a standard telephone line. Because a computer is digital (works with discrete electrical signals representing binary 1 and binary 0) and a telephone line is analog (carries a signal that can have any of a large number of variations), modems are needed to convert digital to analog and vice versa.

motherboard
The main circuit board containing the primary components of a computer system. This board contains the processor, main memory, support circuitry, and bus controller and connector. Other boards, including expansion memory and input/output boards, may attach to the motherboard via the bus connector.

MPR-II
Swedish standard that defines both the electrical and magnetic frequencies.

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N

network
An arrangement of two or more computers interconnected by a communication system.

network adapter
Also called interface adapter; an expansion card or other device used to connect a computer to a local area network.

network address
In a network, every node has one or more addresses associated with it, including a Hardware address assigned by the device's manufacturer. Most nodes also have protocol-specific addresses assigned by a network manager.

Network Interface Card (NIC)
A card with the necessary software and electronics to enable a device to communicate over a network.

node
A device on a network. A point to which communications can be addressed. A receive and send point.

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O

Object Linking and Embedding (OLE)
A technique exploiting the properties of objects to enable two applications to exchange information without the need for human action. In some systems, a whole spreadsheet or a portion of one may be captured as an object and 'embedded' in another application, such as a database. Changes in the value of cells in the spreadsheet will then automatically update the database.

Object Oriented Programmed System (OOPS)
Despite the rather unfortunate acronym, Object Oriented Programmed Systems are seen by many as an important advance. Software tools for OOP have been under development for some years promising a level of re-usability of written code, and practical applications are beginning to appear. Initial OOPS business software applications, however, have failed to live up to expectations in the area of re-usability, suggesting that OOPS is still somewhat a Tools Vendor's marketing strategy, and not yet a major advance in business software development.

ohm
The unit of measure for electrical resistance. A resistance of 1 ohm will pass 1 ampere of current when a voltage of 1 volt is applied.

OLE Automation
The protocol and syntax that defines and manages the exchange of data and control between an OLE Server and OLE Client applications.

Open Database Connectivity (ODBC)
A technology and set of standards based on SQL and now published by Microsoft, enabling any conforming database to be accessed readily via ODBC Comms Drivers by applications written in any ODBC conforming language.

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P

parity error
A crude method of detecting an error in memory or disk. An additional bit is added to each byte. This bit is set at 1 or 0 so that the total number of '1's in the extended byte is even. Byte Parity bit Result 10110101 (1) Even number of '1's = Parity OK 00001100 (0) Even number of '1's = Parity OK 00001100 (1) Odd number of '1's = Parity Error All bytes are checked for even parity as they are loaded into the processor. If any byte is found to have odd parity, an error message is sent to the monitor screen, and usually the process is aborted. There are now more precise error detection and correction methods.

Progammable Logic Controller (PLC)
A class of industrially hardened devices that provides a hardware interface for input sensors and output actuators. PLCs can be programmed using relay ladder logic to control the outputs based on input conditions and / or algorithims contained in the memory of the PLC.

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Q

queue
A data structure from which things are removed in the same order that they were added, also known as FIFO - first in, first out.

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R

random access
Allowing direct access to any item regardless of its location within memory or storage device.

Random Access Memory (RAM)
So called because it provides equally rapid access to every item of information stored, regardless of location. This contrasts with sequential access devices, such as tape, where items of information can be accessed only in the sequence in which they were originally stored. Unlike ROM, RAM can be compared to a blackboard or slate, on which you can write, erase what you wrote, and write something else again and again. It holds programs and data which may be instantly needed by the Processor from moment to moment, and it acts as a scratch-pad for storing intermediate results in calculations.

Redundant Arrays of Independent Disks (RAID)
A fault-tolerant disk architecture which protects systems during a read or write process. Originally the word 'inexpensive' was used instead of 'independent' because low-cost 3.5 inch and 5.25 inch disks were used. RAID disk systems enable the replacement of faulty disks without a long period of down time.

refresh rate
The frequency with which a video display receives its display signals. Under 60Hz refresh rates will produce noticeable screen flickers. Higher refresh rates allow higher screen resolution, and cause less eyestrain.

relational database
A database in which items in different tables are inherently related via common elements. Strictly, to qualify as a true relational database, the data structure and relationships must follow strict rules, that guarantee logical coherence and ensure that information can be accessed from the maximum possible number of viewpoints. These rules were developed by Dr E.F. Codd of IBM.

remote access
Access to a network in another location

RS232
A standard for serial transmission of data between two devices. This defines the pin and plug in terms of size, shape and number of pins. An interface based on the RS232 standard.

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S

sampling rate
The frequency with which samples of a physical variable, such as sound are taken. The higher the sampling rate, the more closely the digitized result resembles the original.

SCSI
A standard set of protocols in a controller for connecting multiple peripherals at up to 40MB/second, removing the need for multiple connecting devices.

serial interface
Relating to the electrical interconnection between the computer and peripheral units (for instance, a printer) in which data is transmitted 1 bit at a time over a single wire.

serial port
A computer interface for connecting to external drives where data is transferred serially.

server
A set of programs providing a service to other client programs; any machine dedicated to the task of providing a specific service or storing data and providing specified sets of data at the request of client machines.

SQL Server
One of the leading proprietary relational database management systems for client/server systems. Both Sybase and Microsoft supply their own versions of SQL/Server. SQL Windows An advanced Windows Client/Server application development environment.

Statistical Process Control (SPC)
A method of clooecting data from a manufacturing process, using statistical calculations to draw conclusions about the process, and using that information to control the process tp prevent unwanted tendencies. This method of process control was popularized by W. Edwards Deming.

Statistical Quality Control (SQC)
General management of quality, cause and effect analysis, and compliance to industry standards.

Structured Query Language (SQL)
Software using a pre-defined set of English language commands, originally intended to enable non-specialist users to extract and use information from relational databases. Results generated by SQL can be formatted to suit screen display or print. SQL is now a de facto standard for relational database management systems, though not quite an easy-to-use tool for the average non-specialist.

Supervisory Control and Data Acquistion (SCADA)
The level of appliactions that monitor and control devices such as programmable controllers. These systems are usually PC or workstation based.

System Integration (SI)
The process of connecting systems, devices, and programs together in a common architecture so as to share and exchange data.

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T

Telephony Applications Programming Interface (TAPI)
Microsoft's API for interfacing Windows-based CTI applications with a telephony environment.

Telnet
TCP/IP for remote terminal connection to a network server.

terabyte (Tb)
Approximately 1,000,000,000,000 or 10 to the power of 12 characters of stored information (Actually 2 to the power of 40 or 1,099,511,627,776 because of the binary basis of computers)

Total Quality Management (TQM)
A method of controlling products, procedures, and systems to produce the optiaml performance in an organization. TQM transcends the level of process control in that it includes management of every aspect of the enterprise, including sales, manufacturing, marketing, shipping, and administration.

transfer rate
The rate at which a circuit or communications channel transfers information from source to destination, as over a network or to and from a disk drive; usually measured in bits per second (bps) or characters per second (cps).

Transmission Control Protocol/Internet Protocol (TCP/IP)
A popular standardized protocol found in Unix environments and throughout the Internet. TCP/IP was developed by the Department of Defense for communication between computers.

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U

Uninterruptible Power Supply (UPS)
A series of batteries through which the main supply is passed. Should the main supply fail, the batteries ensure continuity of power to the computer for a short time, allowing the computer to shut down in an organized way and avoiding corrupted or incomplete data files.

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V

Very Low Frequency (VLF)
Defines frequency range from 3,000 to 30,000 Hz. This type of radiation is emitted from the monitor's deflection yoke.

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W

WAN Wide Area Network
A network that connects users at separate geographical sites, often covering several cities or countries, and in some cases spanning the globe.

What You See Is What You Get (WYSIWYG)
Applies to software systems that display printed material on the screen just as it will appear when printed. This helps the operator to make changes to the printed layout without continually reprinting the document. It is one of the major advantages of Graphical User Interface (GUI) word processor over their character-based predecessors, which were not generally capable of WYSIWYG displays.

Workstation
In general, a combination of input, output and computing hardware that can be used for work by an individual. More often, however, the term refers to a powerful stand-alone computer of the sort used in computer-aided design and other applications requiring a high-end machine with considerable calculating or graphics capability.

World Wide Web (WWW)
A Global network information retrieval system developed by CERN. The World Wide Web is now synonymous with the Internet.

X

Y

Z