Definitions

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Contents
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[edit]

Absolute path A path at begins at the root and includes all successive subdirectories.

Abstract Data Type (ADT) A container whose properties (data and operations) are specified independently of any particular implementation.

Abstract step An algorithmic step for which some details remain unspecified.

Abstraction A model of a complex system that includes only the details essential to the viewer.

Access Control Policy A set of rules established by an organization that specify which types of network communication are permitted and denied.

Access time Thetime it takes for a block to start being read; the sum of seek time and latency.

Adder An electronic circuit that performs an addition operation on binary values.

Addressability The number of bits stored in each addressable location in memory.

Address binding The mapping from a logical address to a physical address.

Address vertices Two vertices that are connected by an edge.

Aggregate opeartion An operation on a data structure as a whole, as opposed to an operation on an individual component of the data structure.

Algorithm Unambiguous instructions for solving a problem or subproblem in a finite amount of time using a finite amount of data.

Analog data A continuous representation of data.

Antivirus software Software designed to detect, remove, and/or prevent malicious software.

Application software Programs that help one solve real-world problems.

Arguments The identifiers listed in parentheses on the subprogram call; sometimes called actual parameters.

Arithmetic/Logic Unit (ALU) The computer component that performs arithmetic operations (addition, subtraction, multiplication, division) and logical operations (a comparison of two values).

Artificial Intelligence (AI) The study of computer systems that model and apply the intelligence of the human mind.

Artificial Neural Networks (ANN) A computer representation of knowledge that attempts to mimic neural networks of the human body.

Assembler A program that translates an assembly-language program into machine code.

Assembler directives Instructions to the translating program

Assembler language A low-level programming language in which mnemonics represent each of the machine-language instructions for a particular computer.

Asynchronous Not occurring at the same moment in time as some specific operation of the computer; in other words, not synchronized with the program's actions.

Attribute Part of a tag that provides additional information about the element.

Authenteication credenteials Information users provide to identify themselves.

Availability The degree to which authorized users can access information for legitimate purposes.

B[edit]

Back door A program feature that gives special and unauthorised access to a software system to anyone who knows it exits.

Bandwidth The number of bits or bytes that can be transmitted from one place to another in a fixed amount of time.

Base The foundational value of a number system, which dictates the number of digits and the value of digit positions.

Base register A register that holds the beginning address of the current partition.

Big-O Notation A notation that expresses computing time (complexity) as the term in a function that increases most raidly relative to the size of the problem.

Binary digit A digit in the binary number system; a 0 or 1.

Binary file A file that contains data in a specific format, requiring a special interpretation of its bits.

Binary tree An abstract composite structure with a unique starting node called the root, in which each node is capable of having two child nodes and in which a unique path exits from the root to every other node.

Biometrics Using physiological characteristics, such as fingerprints, to identify users and control access.

Bit A binary digit.

Block The information stored in a sector.

Boolean algebra A mathematical notation for expressing two-valued logical functions.

Boolean expression A sequence of identifiers, separated by compatibly operators, that evaluates to either true or false.

Bounds register A register that holds the length of the current partition.

Breadth-first approach Searching across levels of a tree prior to searching down specific paths.

Broadband Network technologies that generally provide data transfer speeds greater than 128Kbps.

Buffer overflow A defect in a computer program that could cause aystem to crash and leave the user with heightened privileges.

Bus topology A LAN configuration in which all nodes share a common line.

Bus width The number of bits that can be transferred in parallel over the bus.

Byte Eight binary digits.

Bytecode A standard machine language in which Java source code is compiled.

C[edit]

Cable modem A device that allows computer network communication using the cable TV hookup in a home.

Cache memory A type of small, high-speed memory used to hold frequently used data.

Caesar cipher A substitution cipher that shifts characters a certain number of positions in the alphabet.

Cancellation error A loss of accuracy during addition or subtraction of numbers of widely differing sizes, due to limits of precision.

CAPTCHA A software mechanism used to verify that a web form is submitted by a human and not an automated program.

Cardinality constraint The number of relationships that may exist at one time among entities in an ER diagram.

Case sensitive Uppercase and lowercase letters are not considered the same; two identifiers with the same spelling but different capitalization are considered to be two distinct identifiers.

Cell An element of a spreadsheet that can contain data or a formula.

Character set A list of characters and the codes used to represent each one.

Chatbot A program designed to carry on a conversation with a human user.

Cipher An algorithm used to encrypt and decrypt text.

Circuit A combination of interacting gates designed to accomplish a specific logical function.

Circuit equivalence The same output for each corresponding input-value combination for two circuits.

Circular reference A set of formulas that ultimately, and erroneously, rely on each other to compute their results.

Class (implementation phase) A pattern for an object.

Class NP problems Problems that can be solved in polynomial time which as many processors are desired.

Class P The class made up of all polynomial-time algorithms.

Class P problems Problems that can be solved with one processor in polynomial time.

Client/server model A distributed approach in which a client makes requests of a server and the server responds.

Cloud computing A service that provides storage space and other resources on the Internet.

Code-coverage (clear-box) testing Testing a program or subprogram based on covering all the statements in the code.

Combinational circuit A circuit whose output is solely determined by its input values.

Comment Explanatory text for the human reader.

Compiler A program that translates a high-level language program into machine code.

Compression ratio The size of the compressed data divided by the size of the uncompressed data.

Computational biology An interdisciplinary field that applies techniques of computer science, appl;ied mathematics, and statistics to problems in biology.

Computer gaming A computer simulation of a virtual world.

Computer hardware The physical elements of a computing system.

Computer network A collection of computing devices connected so that they can communicate and share resources.

Computer software The programs that provide instructions that a computer executes.

Computer system Computer hardware, software, and data, which interact to solve a problem.

Concrete step A step for which the details are fully specified.

Confidentially Ensuring that data is protected from unauthorized access.

Constant time An algorithm whose Big-O work expression is a constant.

Containers Objects whose role is to hold and manipulate other objects.

Context switch The exchange of register information that occurs when one process is removed from the CPU and another takes its place.

Control abstraction The separation of the logical view of a control structure from its implementation.

Contrl structure An instruction that determines the order in whichother insutrctions in a program are executed.

Control unit The computer component that controls the actions of other components so as to execute instructions in sequence.

Central Processing Unit (CPU) A combination of the arithmetic/logic unit and the control unit; the "brain" of a computer that interprets and executes instructions.

CPU scheduling The act of determining which process in memory is given access to the CPU so that it may execute.

Cryptanalysis The process of decrypting a message without knowing the cipher or key used to encrypt it.

Cylinder The set of concentric tracks on all surfaces.

D[edit]

E[edit]

F[edit]

G[edit]

H[edit]

I[edit]

Input Unit is a device that accepts data to be stored in the memory.

Instruction Register (IR) is the register that contains the instruction currently being executed.

J[edit]

K[edit]

L[edit]

M[edit]

Memory Management is the act of keeping track of how and where programs are loaded in main memory.

Motherboard is the main circuit board of a computer.

Multiprogramming is the technique of keeping multiple programs in main memory at the same time, competing for the CPU.

N[edit]

O[edit]

Operating System is system software that manages computer resources and provides an interface for system interaction.

Output Unit is a device that prints or otherwise displays data stored in memory or makes a permanent copy of information stored in memory or another device.

P[edit]

Pipelining is a technique that breaks an instruction into smaller steps that can be overlapped.

Process is the dynamic representation of a program during execution.

Process Management is the act of keeping tack of information for active processes.

Program Counter (PC) is the register that contains the address of the next instruction to be executed.

Q[edit]

R[edit]

Register is a small storage area in the CPU used to store intermediate values or special data.

S[edit]

System Software are programs that manage a computer system and interact with hardware.

T[edit]

U[edit]

V[edit]

W[edit]

X[edit]

Y[edit]

Z[edit]