Computer Science GCSE Data Representation

Flashcards for the whole spec except 3.2

Binary

A base2 number system used in computer programs

Bit

A single unit of data (1 or 0)

Byte

8 bits

Nibble

4 bits

Kilobyte

1000 bytes

Megabyte

1000 kilobytes

Gigabyte

1000 megabytes

Terrabyte

.1000 gigabytes

Hexadecimal

A base16 number system used to avoid overly long binary numbers

ASCII

7 bit representation for letters, only 127 characters

Unicode

16 bit representation for all characters

Bitmap

An image made of pixels

Pixels

Little squares that make up images

Colour depth

The number of bits used to represent all colours in an image

Resolution

Clarity of image/sound

Metadata

The data stored in relation to an image (eg. size, name, location…)

Hertz

The frequency and pitch of a sound bit.

Amplitude

Height of a sound wave

Sample rate

Number of samples recorded per second

Sample resolution

Number of bits used to record each sample

Plaintext

Text not encoded or written in code

Cyphertext

Encoded plaintext/code text

Keys

Method for encryption/decryption