ASCII (pronounced "a-ski") stands for American Standard Code for Information Interchange.

It is an encoding standard that assigns a specific number to each letter, digit, and symbol on a computer keyboard. Think of it as a universal dictionary that allows different computers, programs, and devices to "understand" and display text in the same way.

Originally, the ASCII code used 7 bits to represent 128 characters, including all uppercase and lowercase letters of the English alphabet, numbers 0 through 9, punctuation marks, and control characters (such as "enter" and "delete").

Later, extended 8-bit versions were created to include 128 more characters, such as accented letters and other symbols. Today, ASCII has been largely replaced by more comprehensive standards such as Unicode (and UTF-8), which support virtually all alphabets and symbols in the world. However, ASCII still forms the basis of these modern systems.