A character set is a defined list of characters that is recognized by a computer. This allows the computer to recognize the input, and to accurately depict that information so as to be recognizable to the user.

A character is any symbol in a software program that requires one byte of storage. This includes character-based systems, such as ASCII and extended ASCII characters, and geometrical symbols that appear on a computer's screen. In graphics-based applications, character sets include letters, numbers, and punctuation symbols.

There are many character sets. Programming languages, such as HTML, for example, have unique character representations that require a character set. The ASCII character set uses the numbers 0 through 127 to represent all English characters and selected symbolic characters. Other character sets, under the umbrella of the European International Standards Organization (ISO), are similar to the ASCII set. However, the ISO sets contain additional characters that are of relevance to European spoken, or natural, languages.