Data representation

Gigabyte (GB)

Approximately 1,000 megabytes; used to measure large files or storage capacity.

Character Set

A collection of characters and symbols used for data representation.

ASCII (American Standard Code for Information Interchange)

A 7-bit character encoding standard representing English characters, with codes ranging from 0 to 127.

Unicode

A character encoding standard that extends ASCII.

Advantages:

• Can represent a wider range of characters;

• Can represent characters from a wider range of languages;

• Can represent characters used in scientific / mathematical documents;

Pixel

The smallest unit of a digital image, representing a single point in the image.

Bitmap

An image composed of a grid of pixels, each with a specific color and intensity.

Colour Depth

The number of bits used to represent the color of a single pixel, determining the range of colors in an image.

(2ⁿ (where n is the bit depth) = number of colours available)

Image Resolution

The dimensions of an image, typically measured in pixels (width x height), affecting image clarity and detail.

Analogue Sound

Continuous sound waves representing varying frequencies and amplitudes.

Digital Sound

Sound represented by discrete samples, converted from analogue signals.

Sampling Rate

The number of samples of audio taken per second during analogue-to-digital conversion, measured in hertz (Hz).

Sample Resolution

The number of bits used to represent each audio sample, affecting sound quality.

Lossless Compression

Reduces file size without any loss of data, preserving original quality.

Lossy Compression

Reduces file size by removing some data, often unnoticeable to users, but some quality is lost.