Data Types

The five data types are the five categories that data can belong to.

Text
Text is a sequence of symbols which are part of a language. Some languages like English use a set of symbols to form words while languages like Chinese have a single symbol representing a word. The languages which computers use for programming are called artificial languages. Because of the limited range of symbols text is the easiest to store with each symbol taking up one byte. However, since a byte can only store numerical values, each text symbol is converted into a number. Methods such as ASCII have been developed for this use.

Numerical
Numerical data represent pure numbers used for measurements and calculations. These numbers are stored in bytes using the binary system. A single byte can store a number from 0 to 255. To store larger numbers bytes need to be joined together to form "words". A word of 2 bytes can store a number as big as 65535.

Audio
Audio data measure the volume and pitch of a sound. On an average CD there is, on average, 44210 measurements taken per second. Audio data involves the process of digitising where values are created from measurements of real world data.

Image
Image data is data that uses 6 hexidecimal digits as a code, which is translated into colours when displayed.

Image data can be displayed as raster graphics or vector graphics.

Video
Video and audio data have a great deal in common - both are a sequence of measurements. In digital video, measurements are made of:

• the colour and brightness detected by individual light collection points in a digital video camera, or

• the video signal from a traditional video camera or VCR.

In both cases the measurements represent pixels in the image of a single frame. There may be up to 30 frames of data that have to be processed every second. This makes video data the most complicated and certainly the largest of the five data types. ﻿

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