All Keywords Flashcards
To make sure you understand all of the keywords required for the GCSE
1
Q
Accumulator
A
Register that stores the results of any calculations made by the ALU.
2
Q
Adware
A
Software that automatically displays advertising when a user is online
3
Q
Algorithm
A
A series of steps designed to solve a mathematical or other problem
4
Q
Arithmetic and logic unit (ALU)
A
Performs all the arithmetic and logical operations within the CPU
5
Q
Analogue
A
Continuously changing values
6
Q
AND
A
A logic gate that outputs 1 if both inputs are 1
7
Q
Application
A
Software designed to carry out a useful real-world task
8
Q
ASCII (American Standard Code for Information Interchange)
A
A 7-bit code to represent a set of characters available to a computer
9
Q
Assembler
A
Software that translates an assembly language program back into machine code
10
Q
Assignment
A
Setting the value of a variable or constant
11
Q
Binary
A
A number sytem based on 2, using just two symbols: 0 and 1
12
Q
Bit
A
Binary digit 0 or 1: symbol b
13
Q
Bit depth
A
The number bits used to store each sound sample
14
Q
Bit rate
A
The number of bits used to to store a second of sampled sound
15
Q
Boolean algebra
A
A method of expressing mathematically a logic circuit
16
Q
Bus
A
A part of the computer architecture that transfers data and signals between the components of the computer
17
Q
Byte
A
Eight bits : symbol B
18
Q
Cache memory
A
Special high-speed memory used by a computer
19
Q
Central processing unit (CPU)
A
Contains the control unit, ALU and cache memory
20
Q
Channel
A
A communication link carried on any suitable medium such as a wire conductor , fibre-optic cable or wireless signal; for example a bit-stream can be sent between devices on a WLAN along a channel formed by a sub-frequency in a WIFI frequency band
21
Q
Character set
A
The complete set of characters available to a computer
22
Q
Clock chip
A
The electronic device in a computer that controls the timing of signals
23
Q
Colour depth (bit depth)
A
The number of bits used for each pixel
24
Q
Command line
A
The place where commands can be given to the operating system
25
Compression
Reduction in file size to lessen download times and storage requirements
26
Computational thinking
Applying the methods of computer scientists to problem solving
27
Computer architecture
The internal, logical structure and organisation of the computer hardware
28
Constant
A label referring to a location in memory containing a value that can be accessed but not changed by a program
29
Control system
Control machinery and probably only provide limited output for humans to respond to
30
Control unit
Works with the CPU to control the flow of data within the system and to decode instructions
31
Current instruction register (CIR)
Stores the next instruction ready to be decoded
32
De-encapsulation
Removing the data from inside an encapsulated item
33
Declaration
Identifying a variable, constant or array to a program so that memory can be allocated for it
34
Dedicated system
A system performing a single function or set of functions
35
Defragmenter
Software that brings together fragments of files on a disk and collects all the free space in one area
36
Denary
A number system based on 10, using ten digits: 0-9
37
Dual-core/quad-core processor
A CPU with multiple processors: a dual-core has two; a quad-core has four
38
Embedded system
A computer system that forms part of an electronic device
39
Encapsulation
Enclosing the data inside another data structure to form a single component
40
Ethernet
A set of standards used to connect devices in a LAN. Nowadays it tends to use mainly UTP and fibre-optic links or WiFi standards. Ethernet networks split messages into units called frames. Ethernet is still widely used and provides reliable and high-speed links.
41
Fetch-decode-execute cycle
The process of fetching the instructions from memory , decoding them and then executing them that the CPU performs continuously
42
File
Stored data saved on a suitable medium
43
Firewall
Software that limits access to and from a computer system
44
Firmware
Software that is stored permanently on a device
45
General-purpose computer
Systems that can be programmed to perform a wide range of tasks
46
Hexadecimal
A number system based on 16 that uses the symbols 0 - 9 and A - F (to represent the denary values 10 - 15)
47
Instruction set
The complete set of instructions that a processor can handle
48
Instructions
A set of commands that a processor can recognise and act upon
49
Interoperable
The ability of different systems and software applications to communicate and exchange data, and to use the information that has been exchanged
50
Iteration (repetition)
Where a group of instructions is executed repeatedly until a condition is met, or while a condition is true (a loop)
51
Keylogger
A program that records every keystroke of the computer user; often used to gain confidential information in order to commit fraud
52
Kilobyte
1024 bytes
53
Layering
Rules organised into a distinct order in which they need to be applied
54
Logic circuit
A circuit made by combining a sequence of logic gates
55
Logic error
When the logical structure of a program produces unexpected results
56
Logic gate
A circuit that produces an output based on the inputs
57
Memory address register (MAR)
Stores the location for data to be fetched from or sent to memory
58
Memory data register (MDR)
Stores data that has been fetched from or is waiting to be sent to memory
59
Metadata
Data about data. In the case of an image, information about the image data that allows the computer to recreate the image from the binary data in the file
60
Non-volatile memory
Retains data even when the power is turned off
61
NOT
A logic gate that outputs the opposite value to the input
62
Object code
The machine code produced by the compiler
63
Opcode
The part of the instruction that tells the CPU what operation is to be done
64
Operand
The part of the instruction that tells the CPU what to apply the operation to
65
OR
A logic gate that outputs 1 if either, or both, or the two inputs is 1
66
Overflow
When a number becomes too large to store in the number of bits allocated, it is said to 'overflow' and some bits are 'lost', leaving an incorrect value
67
Pixel
A pixel is the smallest element of an image. Pixels are the dots that make the image on the screen
68
Platform
A combination of hardware and operating system that supports the running of particular applications
69
Program
A self-contained set of instructions that can be stored and used by the processor
70
Program Counter (PC)
Stores the location of the next instruction in a program to be executed
71
Programming language
A means of writing programs in a form that can be passed to a computer to process
72
Protocol
Set of rules and standards governing how networks should function and communicate
73
Random access memory (RAM)
The main memory of a computer that stores data, applications and the operating system while in use. When the power is turned off, RAM loses its data
74
Resolution
The number of pixels or dots per unit, for example ppi (pixels per inch) or dpi (dots per inch)
75
Sample rate
The number of times sound is sampled per second, measured in kHz
76
Scheduling
The process of arranging, controlling and optimising work and workloads
77
Selection
A condition to decide a path through the program and which instructions to execute next
78
Sequence
When a list of instructions is carried out in order, one after the other
79
Software
The general term for computer programs
80
Source code
The program written by the end user in a high-level language before it's converted to machine code
81
Spyware
Malicious software that detects what the user is doing and sends details back to the originator of the spyware
82
Syntax error
When the rules of a language are broken by a program
83
TCP/IP (Transfer Control Protocol/Internet Protocol)
A set of protocols that governs the transfer of data over a network
84
Translation
The conversion of human-friendly program writing back to pure machine code
85
Translator
A program that converts high-level or assembly-level commands into machine code
86
Trojan horse
Harmful software disguised as something useful
87
Truth table
A method for recording all possible input combinations and determining the output for each
88
Typecast
Casting a variable using str, int or float
89
Unicode
A character set that uses code pages to provide a range of language symbols. There are several billion possible character codes available to Unicode
90
Utility
A small program designed to carry out a limited maintenance task
91
UTP (unshielded twisted pair)
A common connecting cable made from copper wiring; two wires are twisted around each other to minimise induction and cross-talk between the cables
92
Variable
A label that refers to a location in memory containing a value that can be accessed or changed by a program
93
Virtual machine
An emulation or simulation of a particular computer system or platform that allows programs intended to run on one computer system to run on a different one
94
Virtual memory
A section of the hard disk used as if it were RAM to supplement the amount of main memory available to the computer
95
Virus
A piece of code capable of copying itself, which may damage a system by corrupting it or destroying data
96
Volatile memory
Loses data when there is no power
97
WiFi
A common standard for wireless connectivity based on a standard known as IEEE 802.11. This is a good example of how widely accepted standards have led to practical solutions for connecting devices
98
Worm
Self-replicating, malicious software that can spread through a system or network
