ASCII

ASCII (an acronym for American Standard Code for Information Interchange) is an encoding for various glyphs (written forms such as letters, numbers, etc) into 7-bit numeric form.

The supported set for ASCII includes not only numbers, letters (upper- and lower-case) but also punctuation, and other special-purpose characters (from then-common ones like '@', '#', etc, to others that ASCII has made popular - '^', '|', etc). It also includes non-printing characters used for control of printing terminals - tab, line feed, carriage return, etc.

IBM had its own encoding standard, EBCDIC, which ASCII has gradually superseded.

ASCII also superseded an earlier widespread encoding, SIXBIT, which allowed 6 characters to be carried in the then-common 36-bit words common on many computers, but only supported upper-case characters.