Final answer:
ASCII, which stands for the American Standard Code for Information Interchange, defines a total of 128 characters, including letters, digits, punctuation, and control characters.
Step-by-step explanation:
The American Standard Code for Information Interchange, or ASCII, defines a total of 128 characters. These include standard English letters, digits, punctuation marks, and a variety of control characters. ASCII is a character encoding standard that was developed in the early 1960s and is still used today, primarily to represent text in computers, telecommunications equipment, and other devices that use text. It includes characters from 0 to 127, covering uppercase and lowercase English letters, numbers 0-9, punctuation symbols, and control characters like newline and carriage return.