ASCII

ASCII (American Standard Code for Information Interchange) is a code used to represent romanic characters using 7 bits. It has been widely used in computers and the digital field in general since its creation. It's also known as ISO 646.

Most 8 bit codes (like the ISO 8859-1, ISO 8859-2, etc.) use it as a base for their lower-code characters, and extend it with their specific characters. Even Unicode uses it as a base.

On old terminals, the underscore "_" is displayed as a left arrow, the caret "^" is displayed as an up arrow and the vertical bar "|" has a hole in the middle.

The ASCII standard was published by the United States of America Standards Institute (USASI) in 1968.

Nowadays other standards like Unicode are growing in use because of their multilingual capabilities (using 2 or more bytes)