Unicode System

Unicode is a universal international standard character encoding that is capable of representing most of the world's written languages.

Other standard language systems:

• ASCII (American Standard Code for Information Interchange) for the United States.
• ISO 8859-1 for Western European Language.
• GB18030 and BIG-5 for chinese, and so on.
• KOI-8 for Russian.

Why Java uses Unicode?

The problem was that a particular code value corresponds to different letters in the various language standards. The encodings for languages with large character sets have variable length.Some common characters are encoded as single bytes, other require two or more byte. Thus to solve this two problems unicode system was made which holds 2 bytes thus java also holds 2 bytes for char.