Computers manipulate data: physical or symbolic representations that can be stored, transmitted and transformed. The meaning we assign to those representations is information.

The same information can be represented in many different ways. The number twelve, for example, can appear as the written text 12, the Roman numeral XII, a sequence of two-valued symbols or a set of physical states inside a machine.

Representation and meaning

A representation has meaning only when an agreed interpretation tells us what its symbols or states stand for.

The same stored pattern could represent a number, a character, a color or part of an instruction under different interpretation rules. The physical representation alone does not determine its meaning.

Encoding

An encoding maps information into a representation and, when possible, provides a way to decode that representation again.

Digital systems commonly encode text, images, sound and instructions as finite sequences of discrete symbols.

Processing data

A computer does not need to understand meaning in the human sense to process information. It follows rules that transform representations: compare values, copy stored data, perform arithmetic, select records or transmit messages.

Separating information from its representation is fundamental because many later computing problems concern how the same underlying information is encoded, transformed and interpreted at different layers.