A standard for storing, manipulating, and displaying textual data. The Unicode character set currently (2019) allows for 1 114 112 code points, of which over 137 000 have been assigned characters. Its contents are the same as the Universal Character Set (see UCS), with which its revisions are coordinated. Unicode also specifies various normative classifications for each character (upper-case letter, lower-case letter, decimal number, etc.), rules (e.g. how to decompose a composite character, such as an accented letter, into its component characters), and algorithms (e.g. for collation) as well as reference charts showing the visual form of each character. For backward compatibility the characters assigned to codepoints 0 to 127 are the same as ASCII character set; and those assigned to 0 to 255 Unicode are the same as ISO-8859-1, a superset of Latin alphabet no. 1.
http://www.unicode.org/ The Unicode Consortium home page