It is important to recognize that what the user thinks of as a “character”—a basic unit of a writing system for a language—may not be just a single Unicode code point. Instead， that basic unit may be made up of multiple Unicode code points. To avoid ambiguity with the computer use of the term character， this is called a user-perceived character. For example， “G” + acute-accent is a user-perceived character: users think of it as a single character， yet is actually represented by two Unicode code points. These user-perceived characters are approximated by what is called a grapheme cluster， which can be determined programmatically.
