ASCII (pronounced as-key) is short for American Standard Code for Information Interchange. It is a standard code that assigns a binary number to all the alphanumeric characters (upper and lower case), all the symbols on the keyboard, and some other symbols not on the keyboard (such as the cents symbol: ¢). All computers have been using this standard code for more than a decade, and this is how plain text is saved on a disk. This standard does not define any formatting however (except end of line), so word processors each have their own file type that includes formatting information as well.