ASCII
ASCII is a common historical character encoding, designed to represent English text in digital form. The acronym stands for American Standard Code for Information Interchange. Most of the character encodings in common current use are proper supersets of ASCII: these include the ISO 8859 family of encodings, the Windows 1252 code page and the UTF-8 encoding of the Unicode character set.
Each character is assigned a number from 0 to 127. As well the 26 letters of the English alphabet in upper and lower case, many common punctuation symbols are assigned codes, as well as control characters, such as backspace, carriage return and linefeed.
Because there are 128 separate codes, an ASCII character can be represented by a signed char type in the C programming language.