What are the differences between ASCII and Unicode?

What is ASCII?

ASCII (American Standard Code for Information Interchange) defines 128 characters. The ASCII characters map to the numbers 0–127.

What is Unicode?

Unicode defines 2^21 characters. The Unicode characters map to the numbers 0–2^21. Not all numbers are currently assigned with Unicode character. Some of the numbers are reserved.

Differences between ASCII and Unicode?

ASCII Unicode
Defines 2^7 characters (Extended has 2^8) Defines 2^21 characters
Subset Superset
Numbers 0–127 of ASCII has the same meaning similar to Unicode Numbers 0–127 of Unicode has the same meaning similar to ASCII


Unicode links: