Unicode system stands for universal international standard character encoding.
It provides its own capability to represent the most of the written languages in the world.

Some other codes are:
ASCII (American standard for information interchange)
ISO 8859-1 ( Western European)
KOI-8 (Russian)
GB18030 and BIG-5 (china)

The above languages causes following two problems:

1. The particular code corresponds to the different letter in Various languages standard.
2. Encoding for large character set needs large variable lengths. some common character encoded as a single byte, other required two or more bytes.

So in this Unicode system, Character holds 2 bytes, so java also uses 2 bytes for a character.

Lowest value: "\u0000"
Highets value: "\uFFFF"