What is ASCII and what are ASCII vs. Non-ASCII domains?

ASCII, pronounced ask-ee, stands for the American Standard Code for Information Interchange. ASCII was originally based on the English alphabet and consists of 128 characters including A-Z, 0-9, punctuation, spaces, and other control codes that can be found on a standard English keyboard. These 128 characters are then assigned a number from 0 to 127 to represent them in data transfer from one computer to the other.

ASCII domains are also based on the English alphabet, but are limited to include the characters A-Z, 0-9, and dashes (-). Other types of punctuation, spaces, etc. are not allowed.

Non-ASCII domains are called Internationalized Domain Names (IDNs). More recently, international domain extensions have also become available in a variety of languages and scrips. Both of these types of domains allow for much larger variety of characters, languages, and scripts, opening up the Internet to more people around the world.