In some contexts (especially computer storage and communication) it makes sense to distinguish a character set or character repertoire, which is the whole mapping between a full set of characters and integers, from a character encoding (in a more narrow sense of the term) which specifies how to represent characters from that set using a smaller number of codes. For example, the full repertoire of Unicode encompasses millions of characters, each with a unique 32-bit code. But since most applications use only a small subset, there are more efficient ways to represent Unicode characters in computer storage or communications using only 8-bit bytes, for example, UTF-8. This type of character encoding (which could also be considered a simple text encoding) uses data compression techniques to represent a large repertoire with a smaller number of codes.
Popular character encodings:
See also Text encoding, Unicode.