ASCII (/ˈæski/ ASS-kee), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable and 33 control characters – a total of 128 code points. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers; for example, the first 128 code points of Unicode are the same as ASCII.
ASCII encodes each code-point as a value from 0 to 127 – storable as a seven-bit integer. Ninety-five code-points are printable, including digits 0 to 9, lowercase letters a to z, uppercase letters A to Z, and commonly used punctuation symbols. For example, the letter i is represented as 105 (decimal). Also, ASCII specifies 33 non-printing control codes which originated with Teletype devices; most of which are now obsolete. The control characters that are still commonly used include carriage return, line feed, and tab.