Source : Free On-Line Dictionary of Computing

lexical analysis
     
         (Or "linear analysis", "scanning") The first
        stage of processing a language.  The stream of characters
        making up the source program or other input is read one at a
        time and grouped into {lexeme}s (or "tokens") - word-like
        pieces such as keywords, identifiers, {literal}s and
        punctutation.  The lexemes are then passed to the {parser}.
     
        ["Compilers - Principles, Techniques and Tools", by Alfred
        V. Aho, Ravi Sethi and Jeffrey D. Ullman, pp. 4-5]
     
        (1995-04-05)