ASCII stands for the American Standard Code for Information Interchange, and is pronounced with a hard 'c' sound, as ask-ee. As a standard, ASCII was first adopted in 1963 and quickly became widely used throughout the computer world.

ASCII is a way of defining a set of characters which can be displayed by a computer on a screen, as well as some control characters which have special functions. Basic ASCII uses seven bits to define each letter, meaning it can have up to 128 specific identifiers, two to the seventh power. This size was chosen based on the common basic block of computing, the byte, which consists of eight bits. The eighth bit was often set aside for error-checking functions, leaving seven remaining for a character set.