"Roget's Thesaurus is composed of six primary classes. (...) Each class is composed of multiple divisions and then sections. This may be conceptualized as a tree containing over a thousand branches for individual 'meaning clusters' or semantically linked words. Although these words are not strictly synonyms, they can be viewed as colours or connotations of a meaning or as a spectrum of a concept. One of the most general words is chosen to typify the spectrum as its headword, which labels the whole group.