A character encoding system consists of a code that pairs each character from a given repertoire with something else—such as a bit pattern, sequence of natural numbers, octets, or electrical pulses—in order to facilitate the transmission of data (generally numbers or text) through telecommunication networks or for data storage. Other terms such as character set, character map, and code page are used almost interchangeably, but these terms have related but distinct meanings described below.
Common examples of character encoding systems include Morse code, the Baudot code, the American Standard Code for Information Interchange (ASCII) and Unicode.
Morse code was introduced in the 1840s and is used to encode each letter of the Latin alphabet, each Arabic numeral, and some other characters via a series of long and short presses of a telegraph key. Representations of characters encoded using Morse code varied in length.
The Baudot code was created by Émile Baudot in 1870, patented in 1874, modified by Donald Murray in 1901, and standardized by CCITT as International Telegraph Alphabet No. 2 (ITA2) in 1930.