Chapter 1 Definitions Flashcards
Define bit
The basic computing element that is either 0 or 1, and is formed from the words Binary digit
Define binary number system
A number system based on 2 and can only use the values 0 and 1
Define hexadecimal number system
A number system based on the value 16 which uses denary digits 0 to 9 and letters A to F
Define error code
An error message generated from the computer
Define MAC address
Standing for Media Access Control, this address (given in hexadecimal) uniquely identifies a device on the internet
Define IP address
Internet Protocol; identified either as IPv4 or IPv6; it gives a unique address to each device connected to a network identifying their location
Define HTML
HyperText Mark-up Language is used in the design of web pages and to write
Define overflow error
The result of carrying out a calculation that produces a value that is too large for the computer’s allocated word size
Define logical shift
An operation that shifts bits to the left or right in a register; any bits shifted out of a register are replaced with zeroes
Define two’s complement
A method of representing negative numbers in binary; when applied to an 8-bit system, the left-most bit is given the value -128
Define ASCII code
A character set for all the characters on a standard keyboard and control codes
Define character set
A list of the characters that have been defined by computer hardware and software. The character set is necessary so that the computer can understand human characters.
Define Unicode
A character set which represents all the languages of the world
Define sampling resolution
The number of bits used to represent sound amplitude in digital sound recording (also known as bit depth)
Define bit depth
The number of bits used to represent the smallest unit of a sound file
Define colour depth
The number of bits used to represent the colours of a pixel
Define sampling rate
The number of sound samples taken per second in digital sound recording
Define bitmap image
An image made up of pixels
Define pixel
Derived from the term ‘picture element’. This is the smallest element used to make up an image on a display
Define image resolution
The number of pixels in the X-Y direction of an image
Define pixelated (image)
This is the result of zooming into a bitmap image; on zooming out, the pixel density can be diminished to such a degree that the actual pixels themselves can be seen
Define pixel density
Number of pixels per square inch
Define compression
Reduction of the size of a file by removing repeated or redundant pieces of data; this can be lossy or lossless
Define bandwidth
The maximum rate of transfer of data across a network, measured in kilobits per second (kbps) or megabits per second (Mbps)
Define lossy file compression
A file compression method in which parts of the original file cannot be recovered during the decompression process
Define lossless file compression
A file compression method that allows the original file to be fully restored during the decompression process
Define audio compression
A method used to reduce the size of a sound file using perceptual music shaping
Define MP3
A lossy file compression method used for music files
Define MP4
A lossy file compression method used for multimedia files
Define JPEG
From the Joint Photographic Expert Group; a form of lossy file compression used with image files which relies on the inability of the human eye to distinguish certain colour changes and hues
Define run length encoding (RLE)
A lossless file compression technique used to reduce the size of text and photo files in particular
