256 different characters is not enough

Unicode enables the reliable store most of the world's characters in a (2 byte) fixed width mode with 65,564 characters.

Unicode allows 17 "planes" of 2^16 characters. Thus, Unicode characters range from U+0000 to U+10FFFF - a total of 17 * 2^16 or 1,114,112 code points.

As of Unicode 5.0.0, 102,012 actual characters have been assigned to code points.

Character literals in Java are stored as UTF-16 Unicode characters. Each character takes up 16 bits of memory, allowing for representation of a wide range of characters in the Unicode character set.

That depends on your situation. If you have a Unicode-encoded file that you wish to read, you can try to open it with a Unicode-enabled editor, such as SC Unipad (http://www.unipad.org/main/). == ==

Unicode is simply an international standard that assigns numerical values to characters. - LOTS of characters - currently over 136,000 of them; and it is designed in a way that even more can be assigned in the future.