Refers to a coding system that assigns numerical values to characters such as letters, numbers, punctuation, and other symbols. Basic ASCII allows only 7 bits per character (for a total of 128 characters). The first 32 characters are "unprintable" (line feed, form feed, etc. ). Extended ASCII adds an additional 128 characters that vary between computers, programmes and fonts. Computers use these extra characters for accented letters, graphical characters or other special symbols.