ASCII
American Standard Code for Information Interchange, is a 7 bit encoding of characters on computers. (http://cplus.about.com/od/glossar1/g/ascii.htm).
See also http://searchcio-midmarket.techtarget.com/definition/ASCII who state:-
ASCII (American Standard Code for Information Interchange) is the most common format for text files in computers and on the Internet. In an ASCII file, each alphabetic, numeric, or special character is represented with a 7-bit binary number (a string of seven 0s or 1s). 128 possible characters are defined.
UNIX and DOS-based operating systems use ASCII for text files. Windows NT and 2000 uses a newer code, Unicode. ... Conversion programs allow different operating systems to change a file from one code to another.
ASCII was developed by the American National Standards Institute (ANSI).
(Perhaps off topic as ASCII is not used in teaching but it is very useful to understand the concept when dealing with online text, html files etc).
