Unicode Overview

The Unicode Standard is the universal character encoding standard used for representation of text for computer processing. It is fully compatible with the International Standard ISO/IEC 10646-1:1999, and contains all the same characters and encoding points as ISO/IEC 10646. The Unicode Standard provides additional information about the characters and their use. Any implementation that conforms to Unicode also conforms to ISO/IEC 10646.

Unicode provides a consistent way of encoding multilingual plain text and brings order to a chaotic state of affairs that has made it difficult to exchange text files internationally. Computer users who deal with multilingual text, business people, linguists, researchers, scientists, and others, find that the Unicode Standard greatly simplifies their work. Mathematicians and technicians, who regularly use mathematical symbols and other technical characters, also find the Unicode Standard valuable.

The design of Unicode is based on the simplicity and consistency of ASCII, but goes beyond ASCII's limited ability to encode only the Latin alphabet. The Unicode Standard provides the capacity to encode all of the characters used for the written languages of the world. It uses a 16-bit encoding that provides code points for more than 65,000 characters. To keep character coding simple and efficient, the Unicode Standard assigns each character a unique 16-bit value, and does not use complex modes or escape codes. While 65,000 characters are sufficient for encoding most of the many thousands of characters used in major languages of the world, the Unicode standard and ISO 10646 provide an extension mechanism called UTF-16 that allows for encoding as many as a million more characters, without use of escape codes. This is sufficient for all known character encoding requirements, including full coverage of all historic scripts of the world.UTF-16 allows exactly 16 x 65536 additional code points and still uses the two byte entities to represent characters. However those 16 x 65536 characters require two two byte entities (for a total of four bytes) per each character. For more details on the UTF-16, refer to section C.3 of "The Unicode Standard, Version 2.0" from Unicode Consortium, or Annex C of ISO/IEC 10646-1:1999, Information Technology--Universal Multiple-Octet Coded Character Set (UCS) - Part 1: Architecture and Basic Multilingual Plane.