Computing Topics
- Abend
- A procedure to halt a computer program prematurely, ABnormal END.
- Access Time
- The average time interval between a storage peripheral receiving a request to read or write a certain location and returning the value read or completing the write.
- Action Based Planning
- The goal is to determine how to decompose a high level action into a network of sub-actions that perform the required task.
- Active High
- The active, true, one, or asserted case of a binary signal is the high or most positive voltage level.
- Active Low
- The active, true, one, or asserted case of a binary signal is the low or less positive voltage level.
- Active Window
- The top or front window in a multiple window environment.
- Ada
- A large, complex, block-structured computer language aimed primarily at embedded applications.
- Adaptive Learning
- Learning where a system programs itself by adjusting weights or strengths until it produces the desired output.
- Address
- The binary number that represents the collection of binary signals used by memory hardware to determine which memory register to access.
- Advanced Graphics Port
- Slot on the PC motherboard for graphics cards, and the format of the cards themselves - more commonly known by its abbreviation AGP.
- AGP
- Abbreviation of Advanced Graphics Port.
- AI
- Abbreviation of Artificial Intelligence.
- Algol
- A high-level programming language developed in the 1950s.
- Algorithm
- A logical sequence of instructions that explain how to accomplish a task. It must explain exactly how to go from one step to the next and have a finite amount of steps.
- Alphabetics
- The science of representing spoken sounds by letters.
- Alphanumeric
- A character set that contains both letters and digits.
- American Standard Code for Information Interchange
- Coding for text files.
- Ampersand
- The character &
- AND Gate
- Gate that produces a logic 1 when all of its inputs are 1. In all other cases the output is 0.
- Applet
- A small application, often downloaded from a remote server and run in a controlled environment.
- Application
- Software that lets users do relatively complex tasks.
- Arithmetic Error
- As error that occurs when discarding least significant bits of a fixed-point arithmetic operation.
- Artificial Intelligence
- Field of computer science concerned with the concepts and methods of symbolic inference by computer, and the symbolic representation of the knowledge to be used in making inferences.
- ASCII
- Coding for text files.
- Aspect Ratio
- Fo a graphics device it is the ratio of the screen dimensions, normally defined as vertical screen dimension divided by horizontal screen dimension.
- Assembler
- A computer program that converts symbolic assembly language programs into equivalent binary machine language programs.
- Asserted High
- The asserted, true, one, or active case of a binary signal is the high or most positive voltage level.
- Asserted Low
- The asserted, true, one, or active case of a binary signal is the low or less positive voltage level.
- Asynchronous
- The transmission of data between a transmitting and a receiving device that occurs as a series of zeros and ones.
- Auralization
- The technique of using computer-based mathematical models of an acoustic environment and 3D sound processing methods to make audible the sound field of a source in the modeled space.
- Avatar
- A picture or figure representing a person in an online environment.
- Babbage, Charles
- The British inventor known to some as the Father of Computing.
- Bar Code
- Coded labels that contain information about the item they are attached to, the information is contained in a numerical code, usually containing 12 digits.
- Basic
- A high-level programming language designed at Dartmouth College as a learning tool.
- Baud Rate
- The speed of information being transmitted across a serial interface, expressed in units of bits per second (bps).
- Big Endian
- A byte ordering system where the most-significant byte of a multiple byte number is placed in memory at the lowest address.
- Binary Coded Decimal
- A number system where each decimal digit is separately represented by a 4-bit binary code.
- Binary Coded Digit
- A digit of any number system that is represented as a fixed number of binary digits
- Binary Notation
- In order to understand how a number in binary notation is constructed, the decimal notation is first discussed.
- Binary Number
- A number written to base 2.
- Biometrics
- The recognition of people from characteristics such as fingerprints, facial-geometry, iris patterns or voice.
- BIOS
- Acronym for basic input/output system, the commands used to tell a CPU how it will communicate with the rest of the computer.
- Bit
- Binary Digit - the smallest unit of binary data.
- Bit Depth
- The number of bits used to represent each pixel in an image, determining its colour or tonal range.
- Bitmap
- An uncompressed graphics file format.
- Bitrate
- The rate at which the compressed bitstream is delivered from the storage medium to the input of a decoder.
- bits per second
- A measurement of data transmission speed in a communications system, the number of bits transmitted or received each second.
- Bitstream
- An ordered series of bits that forms the coded representation of the data.
- Block Diagram
- A diagram in which the major components of an equipment or a system are represented by squares, rectangles, or other geometric figures, and the normal order of progression of a signal or current flow is represented by lines.
- Boolean
- Pertaining to the operations of formal logic.
- Boot Up
- Literally, the process of loading up the operating system and getting the computer ready for use.
- bps
- bits per second, the number of bits transmitted or received each second.
- Buffer
- A memory location in a computer or digital instrument which is set aside for temporarily storing digital information while it is waiting to be processed.
- Bug
- A mistake or problem in software or hardware.
- Byte
- A group of binary digits that combine to make a word. Generally 8 bits.
- Cache
- Static random access memory containing recently used information.
- Caching
- A process in which frequently accessed data is kept on hand, rather than constantly being from the place where it is stored.
- CAD
- Abbreviation of Computer Aided Design.
- CAE
- Abbreviation of Computer Aided Engineering.
- Cascading Style Sheets
- Set of HTML commands used to control the style of web pages - commonly known by abbreviation CSS.
- Case Based Reasoning
- Solves a current problem by retrieving the solution to previous similar problems and altering those solutions to meet the current needs.
- Cathode Ray Tube
- An evacuated tube containing an anode and a cathode that generates cathode rays when operated at a high voltage.
- CD
- Abbreviation of Compact Disc, an optical disc designed to store digitally 74 minutes of stereo audio data.
- cdrom
- Abbreviation that stands for Compact Disc Read Only Memory.
- Central Processing Unit
- The computer chip primarily responsible for executing instructions.
- CFD
- Abbreviation of Computational Fluid Dynamics.
- Checksum
- A number formed by an algorithm, possibly addition, applied to a data record.
- CMYK
- Cyan, magenta, yellow, and black are the base colours used in printing processes.
- Code
- When used as a verb, code means to write a program. As a noun, code refers to the binary instructions of a program.
- Cognition
- The processes of human or animal thought. The acquisition, understanding, representation and manipulation of knowledge.
- Cognitive Science
- The study of thought processes in animals and machines.
- Compact Disc
- An optical disc designed to store digitally 74 minutes of stereo audio data.
- Compiler
- A computer program that translates high-level language statements to machine language.
- Computational Chemistry
- A branch of chemistry concerned with the prediction or simulation of chemical properties, structures, or processes using numerical techniques.
- Computational Fluid Dynamics
- A tool for predicting the aerodynamics and fluid dynamics of air around flight vehicles by solving a set of mathematical equations with a computer.
- Compute
- To solve problems that use numbers.
- Computer
- A data processor that can perform substantial computation, including numerous arithmetic or logic operations, without intervention by a human operator during the run.
- Computer Aided Design
- Usually applied to that part of CAE which has to do with the drawing or physical layout steps of engineering design.
- Computer Aided Engineering
- A technique for using computers to help with all phases of engineering design work.
- Computer Aided Engineering Books
- Lists all Computer Aided Engineering Books in the Encyclopaedia
- Computer Aided Engineering Weblinks
- Lists all Computer Aided Engineering Weblinks in the Encyclopaedia
- Computer Assisted Drug Design
- Using computational chemistry to discover, enhance, or study drugs and related biologically active molecules.
- Computer Hardware
- The physical parts of a computer.
- Computer Network
- Lists all Computer Network topics in the Encyclopaedia
- Computer Network Books
- Lists all Computer Network Books in the Encyclopaedia
- Computer Network Weblinks
- Lists all Computer Network Weblinks in the Encyclopaedia
- Computer Software
- The programs that run on a computer.
- Computer Virus
- A program that has been deliberately created to cause computer problems.
- Concatenate
- To link together or place end to end.
- Constant
- A quantity that does not change. This quantity may be a number or a variable.
- Control Variable
- The inputs and outputs which a control system manipulates and measures to keep proper control.
- C Plus Plus Programming Language
- An extension to the C language developed primarily by B.Stroustrup at AT&T Bell Laboratories. It supports object-oriented programming.
- C Programming Language
- A language developed in conjunction with the UNIX operating system at AT&T Bell Laboratories by D. Ritchie and now an ANSI standard. It has grown popular due to its simplicity, efficiency, and flexibility.
- CPU
- Abbreviation of Central Processing Unit, the computer chip primarily responsible for executing instructions.
- Crash
- Slang used to describe a program with errors that cause it to stop functioning correctly.
- Cross Assembler
- An assembler program that runs on a different kind of computer than that for which it generates code.
- CRT
- An evacuated tube containing an anode and a cathode that generates cathode rays when operated at a high voltage.
- Cryptography
- Field of mathematics and computer science concerned with information security and related issues, particularly encryption and authentication.
- CSS
- Abbreviation of Cascading Style Sheets.
- Cursor
- A bright figure used as a pointer on a computer screen.
- Data
- A series of facts or statements that may have been collected, stored, processed or manipulated but have not been organized.
- Data Mining
- Using automated data anlysis techniques to find themes or relationships.
- Database
- Information organised into interrelated tables of data and information.
- Date
- A number or series of numbers used to identify a given day with the least possible ambiguity.
- DaughterBoard
- A board that rides piggyback on another board, such as the motherboard or an expansion card.
- DDR
- Abbreviation of Double Data Rate.
- Debug
- To correct mistakes in both software and hardware.
- Decision Tree
- A graphical representation of a hierarchical set of rules that describe how one might evaluate or classify an object of interest based on the answers to a series of questions.
- Denial of Service
- A form of attack on an internet service, which aims to prevent the service from operating properly, often by bombarding it with more information than it can process.
- Desktop Computer
- A computer designed to sit on a desk.
- DFT
- The Discrete Fourier Transform, the digital version of the fourier transform.
- Dialog Unit
- A unit of relative distance used in computer graphics.
- Digital
- Literally means to do with numbers.
- Digital Computer
- A computer that operates on discrete data by performing arithmetic and logic processes on these data.
- Digital Rights Management
- Software intended to prevent the unauthorised duplication of copyrighted video or audio, usually built into a computer's operating system.
- Digital Signatures
- The electronic equivalent of a signature used for authentication.
- Digital Versatile Disc
- Optical disc used for data, video and audio storage.
- DIMM
- Abbreviation of Dual In-line Memory Module.
- Discrete Fourier Transform
- The digital version of the fourier transform.
- Disk Operating System
- Program used to control the transfer of information to and from a disk, such as MS DOS.
- Display Resolution
- Refers to the number of distinct pixels in each dimension that can be displayed.
- Do Loop
- A programming language statement which allows code to be repeatedly executed.
- DOS
- Abbreviation of Disk Operating System.
- Double Data Rate
- A fast type of RAM for a PC, originally only used on high performance graphics cards but now being used for general memory in most high-end PCs.
- Double Word
- Unit of information equal to 2 short words, 4 bytes or 32 bits.
- DRM
- Abbreviation of Digital Rights Management.
- D-Sub Connector
- A connector whose male end has a D shaped raised shield that protects the connecting pins.
- Dual In-line Memory Module
- A module of RAM for a PC, replacing the older SIMM specification.
- DVD
- Digital Versatile Disc, optical disc used for data, video and audio storage.
- Dynamic Data Exchange
- A protocol for allowing different software applications or programs to share information.
- EEPROM
- Acronym for electrically erasable programmable read only memory.
- Effective Address
- The final memory address used by an instruction.
- EiB
- Abbreviation of exbibyte, equal to two to the power of sixty bytes.
- Entropy
- A measure of the information contained in a message, it's the lower bound for compression.
- EPROM
- Acronym for erasable programmable read only memory.
- Error Correction
- A method using a coding system to correct data errors by use of redundant data within a data block.
- Euler Codes
- Computer software that is a mathematical representation of the motion of a fluid whose behavior and properties are described at fixed points in a coordinate system.
- exbibyte
- Equal to two to the power of sixty bytes.
- Expert System
- Encapsulates the specialist knowledge gained from a human expert and applies that knowledge automatically to make decisions.
- Extensible Markup Language
- Better known in the abbreviated form as XML. XML is a markup language much like HTML.
- FIELDbus
- A communications protocol.
- FIFO Buffer
- A first in, first out, store.
- Firewire
- A very fast external bus standard that supports data transfer rates of up to 400 Mbps.
- Flag
- A variable which can take one of only two values.
- Flash Drive
- A removable data storage device, usually thumb sized and plugged into the USB port.
- Flash Memory
- Non-volatile computer memory that can be electrically erased and reprogrammed.
- Floating Point Number
- A number represented in the computer in mantissa and exponent form.
- Floating Point Operations per Second
- A measure of a computer′s performance, especially in fields of scientific calculations that make heavy use of floating point calculations.
- FLOPS
- Abbreviation of Floating Point Operations per Second.
- For Next Loop
- A programming language statement which allows code to be repeatedly executed.
- Fortran
- From Formula Translation this is a computer programming language that is best known amongst scientists and engineers. Within the engineering community it is being replaced by packages such as Matlab.
- Fractals
- Discovered by Benoit Mandelbrot in 1964.
- Fuzzy Logic
- Invented by Lofti Zadeh in 1962.
- General Purpose Interface Bus
- More commonly abbreviated as GPIB.
- GiB
- Abbreviation of gibibyte, equal to two to the power of thirty bytes.
- gibibyte
- Equal to two to the power of thirty bytes.
- Gigabyte
- One billion bytes.
- GigaFLOPS
- One billion floating-point operations per second.
- GPIB
- Abbreviation of General Purpose Interface Bus, IEEE 488 interface standard.
- Granularity
- The basic size of units that can be manipulated.
- Graphical User Interface
- Abbreviated to GUI and pronounced "gooey". It is the programming code defining the operation and graphics displayed on a computer monitor.
- Graphics Card
- An expansion card which the PC uses to control the output graphics.
- GUI
- An abbreviation of Graphical User Interface, it is the programming code defining the operation and graphics displayed on a computer monitor.
- Handshaking
- The initial exchange between two communications systems prior to and during transmission to ensure proper data transfer.
- Hard Disc Drive
- The main storage for programs and data on a computer.
- HDD
- Abbreviation of Hard Disc Drive.
- Heterogeneous Database
- Database that contains different kinds of data, e.g, text and numerical data.
- Hexadecimal
- Counting system based on 16.
- High Level Language
- A computer language with commands that do not directly represent the machine instructions.
- HMI
- Abbreviation of Human Machine Interface.
- HTML
- Abbreviation of HyperText Markup Language.
- http
- Abbreviation of HyperText Transfer Protocol.
- Human Machine Interface
- The interface between man and machine.
- Hyperlink
- Any kind of link on a webpage.
- HyperText Markup Language
- The system used for creating World Wide Web pages, ordinary text with commands for special effects like pictures, colour and links enclosed between < > symbols.
- IEEE 1394
- A very fast external bus standard that supports data transfer rates of up to 400 Mbps.
- IEEE 488
- Communication standard.
- Index Register
- A microprocessor register that holds part of or all the effective address used by an instruction.
- Information Filtering
- System sorts through large volumes of dynamically generated information to present to the user those nuggets of information which are likely to satisfy his or her immediate needs.
- Inherited Error
- The error in initial values used in a computation; especially the error introduced from the previous steps in a step-by-step integration.
- Input-Output
- The reception and transmission of information between control devices using discrete connection points.
- Instruction
- A binary code number that directs the control unit of a computer to perform a certain operation.
- Instruction Set
- The collection of the instruction codes recognized by the control unit of a computer.
- Interface
- A boundary across which two systems communicate.
- Internet Service Provider
- A company which provides a connection to the internet, or internet services.
- Interrupts
- An efficient method to quickly request a computer′s attention to a particular external event.
- IO
- Abbreviation of Input-Output.
- ISP
- Abbreviation of Internet Service Provider.
- Java
- Object oriented language designed to work on all platforms.
- JavaScript
- An object-oriented scripting language used to enable programmatic access to objects within both the client application and other applications.
- kB
- In SI units this is 1000 bytes.
- Keyboard
- An input device, partially modeled after the typewriter keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches.
- KiB
- Abbreviation of kibibyte, equal to two to the power of ten bytes.
- kibibyte
- Equal to two to the power of ten bytes.
- Kilobyte
- In SI units this is 1000 bytes.
- Knowledge Engineering
- The process of collecting knowledge from human experts in a form suitable for designing and implementing an expert system.
- Landauer′s Principle
- A principle which states that it doesn′t explicitly take energy to compute data.
- Leapfrog Test
- A check routine which eventually occupies every possible position in the memory.
- Least Significant Bit (LSB)
- The bit within a digital word that represents the smallest possible coded value.
- Lempel-Ziv Welch Compression
- Algorithm used by the Unix compress command to reduce the size of files, eg. for archival or transmission.
- Linux
- An open source PC operating system.
- LISP
- Abbreviation for list processing.
- Little Endian
- A byte ordering system where the least-significant byte of a multiple byte number is placed in memory at the lowest address.
- Load
- The weight supported by a structure.
- Logic
- The study of the formal laws of reasoning.
- Logic Circuit
- The primary control information processor in digital equipment; made up of electronic gates and so named because their operation is described by simple equations of a specialized logic algebra.
- Logic Diagram
- Representing the logical elements and their interconnections without necessarily expressing construction or engineering details.
- Logic Operation
- A nonarithmetical operation in a computer, such as comparing, selecting, making references, matching, sorting, and merging, where the logical YES or NO quantities are involved.
- Loop
- In a program, a series of instructions that are repeated a prescribed number of times, followed by an end instruction to terminate the series.
- Machine Learning
- The ability of a computer to automatically gain new knowledge.
- Malware
- Software installed by stealth onto a PC for malevolent purposes.
- Matlab
- High-performance numeric computation language from Mathworks.
- mebibyte
- Equal to two to the power of twenty bytes.
- Memory
- In a computer system memory is used to store data temporarily or permanently. The capacity of the memory is normally measured in bytes.
- MiB
- Abbreviation of mebibyte, equal to two to the power of twenty bytes.
- Microcomputer
- One integrated circuit or a collection of integrated circuits including a microprocessor that make a computer.
- Microprocessor
- The single integrated circuit or the portion of a single-chip microcomputer that implements the processor and control unit of a microcomputer.
- Minuend
- A number from which another number is to be subtracted.
- MODbus
- Communication protocol developed by Modicon; widely used in SCADA and process control applications.
- Modular Number System
- A number system represented best by numbers on a circle because the numbers repeat.
- Moore′s Law
- This states that the number of devices on a silicon chip could double each year.
- MotherBoard
- The main circuit board of a PC to which everything connects.
- Mouse
- A device used to move a pointer around on the computer screen.
- Negation
- The process of inverting the value of a function or variable.
- Neural Network
- An approach to machine learning that tries to replicate the neurons of the brain and relies on being trained.
- NIC
- Abbreviation of Network Interface Card.
- Nonmaskable Interrupt
- A hardware interrupt that software cannot disable.
- Nonvolatile Memory
- A type of memory that retains information without electrical power.
- Offset Binary Coding
- For bipolar signals, offset binary is a digital coding scheme in which the most negative value is represented by all zeros (00000000) and the most positive value is represented by all ones (11111111).
- OpenGL
- A graphics standard providing advanced rendering capabilities.
- Operating System
- The master program that runs automatically when you switch the computer on and is responsible for the many routine tasks required to keep a computer running.
- Parallel Port
- A special socket for plugging a printer into a computer.
- Parallel Transfer
- A transfer of multiple bits from one register to another simultaneously.
- Pattern Recognition
- A computational technique used to find patterns and develop classification schemes for data in very large data sets.
- PCI
- Abbreviation of Peripheral Component Interconnect.
- pebibyte
- Equal to two to the power of fifty bytes.
- Peripheral Component Interconnect
- Standard for PC expansion cards - more commonly known by the abbreviation PCI.
- Perl
- An interpreted language optimised for scanning arbitrary text files.
- PiB
- Abbreviation of pebibyte, equal to two to the power of fifty bytes.
- Picaxe
- The name of a UK-sourced microcontroller system based on a range of Microchip PICs.
- Pointer
- A register that holds an address of data rather than the data.
- POP3
- Abbreviation of Post Office Protocol version 3.
- Post Office Protocol version 3
- A protocol for transmitting and receiving email.
- Powerline Carrier System
- A method of sending information over an electrical power distribution system.
- Program
- A list of instructions that tell a computer how to do something.
- Program Counter
- A microprocessor register that holds the memory address of the next instruction to be fetched.
- Programming Languages
- A list of programming languages with their main fields of use.
- PROM
- An acronym for programmable read only memory.
- Pulse Code Modulation
- Coding where the input signal is represented by a given number of fixed-width samples per second.
- Pure Procedure Code
- Program code that does not modify itself as it runs.
- RAM
- Abbreviation of Random Access Memory, a data storage device for which the order of access to different locations does not affect the speed of access, except for bursts.
- Random Access Memory
- A data storage device for which the order of access to different locations does not affect the speed of access, except for bursts.
- Random Number Generators
- A device used to produce a selection of numbers in a fair manner, in no particular order and with no favour being given to any numbers.
- Really Simple Syndication
- Automated system for gathering information, usually news, from multiple sources and bringing it together in one place, usually a website - more commonly known by abbreviation RSS.
- Recursion
- Given some starting information and a rule for how to use it to get new information, the rule is then repeated using the new information.
- Reduced Instruction Set Computer
- A computer architecture that has reduced chip complexity by using simpler processing instructions.
- Register
- An electronic device that holds a binary number.
- RGB
- Abbreviation of Red, Green, Blue.
- Ribbon Cable
- Any cable constructed as a ribbon with parallel elements.
- RISC
- Reduced Instruction Set Computer, a computer architecture that has reduced chip complexity by using simpler processing instructions.
- ROM
- Read only memory (permanent memory that cannot be changed).
- Rosenbrock Function
- A non-convex function used as a performance test problem for optimization algorithms introduced by Rosenbrock in 1960.
- Round Off Error
- This is error introduced into a calculation by rounding off the results of intermediate steps to values which are close, but not exactly correct.
- RS232
- Serial communications system.
- RS274
- Industry standard programming language.
- RS422
- Industry communication standard for sending signals over distances up to 4000 feet.
- RSS
- Abbreviation of Really Simple Syndication.
- SD Flash Memory card
- Flash memory storage used for digital cameras and other portable devices.
- Sequential Access Memory
- A memory in which access of the registers must be in sequential order.
- Serial Communications
- Transmission of binary data from one device to another one bit at a time.
- Serial InfraRed
- Wireless communication system for PCs and peripherals.
- Sexadecimal
- The same as Hexadecimal.
- Shortword
- A word or shortword is 16 bits.
- Simple Mail Transfer Protocol
- The original method of transmitting and receiving email on the internet.
- SIR
- Abbreviation of Serial InfraRed.
- Smartmedia Flash Memory Card
- Flash memory storage used in digital cameras.
- SMTP
- Abbreviation of Simple Mail Transfer Protocol.
- Soundcard
- Expansion card which enables the PC to make sounds.
- Speech Coding
- Excellent speech quality implies that coded speech is indistinguishable from the original and without perceptible noise.
- Spintronics
- Computer processor that uses the spin of the electron to carry information rather than the charge.
- SQL
- Abbreviation of Structured Query Language.
- SRAM
- An integrated circuit similar to a DRAM with the exception that the memory does not need to be refreshed.
- Static Random Access Memory
- An integrated circuit similar to a DRAM (dynamic random access memory) with the exception that the memory does not need to be refreshed.
- Storage
- The generic term for any method of storing information which is not lost when the computer is switched off.
- Structured Query Language
- A syntax used by many database systems to retrieve and modify information.
- Subroutine
- A previously known algorithm used in another algorithm.
- Subtrahend
- A number that is to be subtracted from another number.
- Sum
- The result of the addition of numbers.
- Supercomputer
- A general term used to describe the fastest available mainframe computers.
- Supervised Learning
- Organization and training of a neural network by a combination of repeated presentation of patterns and required knowledge.
- Synchronous Dynamic Random Access Memory
- SDRAM delivers bursts of data at high speeds using a synchronous interface.
- Syntax
- The rules governing the structure of a language.
- Tautology
- A sentence that is true because of its logical structure.
- tebibyte
- Equal to two to the power of forty bytes.
- Thumb Drive
- Another name for Flash Drive.
- TiB
- Abbreviation of tebbyte, equal to two to the power of forty bytes.
- Timeline
- A brief overview of the major milestones in science and engineering.
- Toggle
- A word meaning to reverse or complement the state of something.
- Toolbox
- A box design to protect and allow a set of tools to be carried around.
- Touchpad
- A pressure-sensitive pad which replaces the mouse on most laptop computers.
- Trojan
- Malware that appears to perform a desirable function for the user but instead facilitates unauthorized access to the user's computer system.
- Truncation Error
- Error resulting from the use of only a finite number of terms of an infinite series or from the approximation of operations.
- Typematic Rate
- The rate at which keys repeat when held down.
- Typematic Rate Delay
- The initial delay before key auto-repeat starts.
- Unicode
- A standard of computer character set.
- Uninterruptible Power Supply
- A type of power supply designed to support the load for specified periods when the line varies outside specified limits.
- Universal Serial Bus
- An external bus standard that supports data transfer rates of 12 Mbps.
- Unsigned Binary Number
- A binary number in which all the bits are used to represent positive quantities.
- UPS
- A type of power supply designed to support the load for specified periods when the line varies outside specified limits.
- USB
- An external bus standard that supports data transfer rates of 12 Mbps.
- USB Memory Stick
- Flash memory with a USB interface built in. A portable storage device that is plug and play.
- Variable
- A letter that is used to represent a numerical quantity whose value may or may not yet be known.
- Variate
- Random variable.
- Veitch Diagram
- A diagram consisting of joined squares, which is used to give a graphic representation of basic logic relations.
- VGA
- Abbreviation of Video Graphics Array.
- Video Graphics Array
- An early colour graphics standard for PCs.
- Volatile Memory
- A type of memory that loses the numbers stored in it when electrical power is removed from it.
- What You See Is What You Get
- The image you see on the screen matches what will print on paper.
- Wiki
- A website where the users create and edit the content collaboratively.
- Windows
- A family of operating systems from the Microsoft Corporation, standard on most PCs.
- Wireframe
- A set of curves that define a surface or a three-dimensional object. The name derives from the appearance of the diagram.
- Word
- An ordered set of bits that is the normal unit in which information may be stored.
- Word Length
- The number of bits in a word.
- World Wide Web Consortium
- Organisation that produces standards for the world wide web.
- Worm
- A malicious program introduced into computers by stealth, similar to a virus.
- WWW
- Abbreviation of World Wide Web.
- Wyde
- The name for 2 bytes or 16 bits.
- WYSIWYG
- Abbreviation of What You See Is What You Get.
- XML
- An abbreviation of extensible markup language, a markup language much like HTML.
- Zip
- A popular standard for file compression developed by the PKWare corporation.
- Zip Drive
- A special drive for removable data cartridges.

