ASCII - American Standard Code for Information Interchange (pronounced ask-ee).

This is the de facto world-wide standard for the code numbers used by computers to represent all the upper and lower-case Latin letters, numbers, punctuation, etc. There are 128 standard ASCII codes each of which can be represented by a 7 digit binary number: 0000000 through 1111111, plus parity.

There are several larger character sets that use 8 bits, which gives them 128 additional characters. The extra characters are used to represent non-English characters - special Latin characters (like accented characters, or German ess-tsett), characters from non-Latin writing systems (e.g., Cyrillic, or Han characters)), graphics symbols, and mathematical symbols. Several companies and organizations have proposed extensions for these 128 characters. The DOS operating system uses a superset of ASCII called extended ASCII or high ASCII. A more universal standard is the ISO Latin 1 set of characters, which is used by many operating systems, as well as Web browsers.

UNIX and DOS-based operating systems (except for Windows NT) use ASCII for text files.

Text editors and word processors are usually capable of storing data in ASCII format, although ASCII format is not always the default storage format. Most data files, particularly if they contain numeric data, are not stored in ASCII format. Executable programs are never stored in ASCII format.

ASCII replaced earlier systems such as EBCDIC and Baudot, which used fewer bytes, but were each broken in their own way.

Some rather inventive individuals have developed what is known as ASCII art, a lowbrow art form in a high-tech medium, using only the ASCII character set to create images.