Source : Free On-Line Dictionary of Computing

UCS transformation format
     
         (UTF) A set of standard {character
        encodings} in accordance with {ISO 10646}.
     
        One of a set of standard character encodings, the most widely
        used of which are UTF-8, UTF-16, and UTF-32.  The code tables
        in ISO 10646 and in the {Unicode} standard are identical,
        although the Unicode standard includes additional material.
     
        UTF-8 is the most widely used encoding, at least on {Unix}
        systems.  Since it does not include any bytes like '\0' or '/'
        which have a special meaning in filenames and other {C}
        library function parameters, and 7-bit ASCII characters have
        the same encoding under both {ASCII} and UTF-8, the required
        changes to existing software are minimised.
     
        Other UTFs: UTF-1 and UTF-7 are not widely used.
     
        {UTF-8 and Unicode FAQ for Unix/Linux
        (http://www.cl.cam.ac.uk/~mgk25/unicode.html#ucs)}.
     
        (2002-01-15)