1.2(b) Units and Data Storage

The smallest part of an . A single dot which has one .

The unit of storage, represented by either a binary 1 or 0.

Half a . bits.

A collection of 8 .

One kilobyte is bytes.

One megabyte is 1000 kilobytes (KB) or bytes

One is 1000 megabytes (MB) or 1000000000 bytes

One terabyte is gigabytes (GB) or 1000000000000 bytes

One petabyte is 1000 (TB) or 1000000000000000 bytes

A base- number system. Only 2 possible values making it and reliable system for electronic systems.

The generation of a that is too to be represented by the device intended to store it.

A base- number system. The 16 digits are 0–9 and the letters A–F. Translates easily to as 1 hex digit is bits. Used in computing as it is to work with than binary.

1 shift left will by 2. 1 shift right will by 2.

Stores of the characters that the computer can represent. Each character is given a binary code. ASCII and are examples of character sets.

A character set that uses 7 bits to each character. This gives a possible different characters. Extended to 8 bits to give 256 possible characters.

A character set that uses 16-24 bits to represent each character. characters can be represented. Global represented. Can store emojis. However, larger file size than ASCII.

A collection of data that describes and provides about other data. For example, image files contain metadata about the and height of the image.

The number of bits used to represent the colour of a single in an image. For example, an image with a 4 bit colour depth will contain a possible 16 different . Higher colour depth = higher and higher file size.

The total number of in an image. The higher the resolution the the quality of the image.

image file size in bits = (width in pixels × in pixels × colour in bits) + metadata (10%)

The number of samples taken per . in Hertz.

The number of bits available to store each . A bit depth of 4 would allow different levels of .

How many of audio a sound file contains.

The quality of the sound file when listened to. The higher the bit depth the the quality. The higher the sample , the better the quality.

total size of sound file = (sample x sample bit depth x sample ) + metadata (10%)

The process of reducing the size. Two types, Lossy Compression and Compression.

File size is reduced significantly by removing data. The data removed may be unnoticeable. However the image will lose quality. For example, removing the number of different in an image.

File size is by storing the data differently. Data is NOT deleted. The original file can be restored. No loss of . Suitable for text files and executable files.