Standard ASCII (American Standard Code for Information Interchange) is the most widely used character encoding standard for computers and communication systems. It assigns unique numbers to 128 characters, including letters, numbers, punctuation marks, and control characters. The ASCII standard was developed in the 1960s and is based on the English alphabet. It includes uppercase and lowercase letters of the English alphabet, numbers (0-9), punctuation marks, control characters, such as the tab, newline, and carriage return characters, a few special characters, such as the @ symbol and the # symbol.