The dictionary is a list of words with their definitions, a list of characters with their glyphs, or a list of words with corresponding words in other languages. In a few languages, words can appear in many different forms, but only the lemma form appears as the main word or headword in most dictionaries. Many dictionaries also provide pronunciation information; grammatical information; word derivations, histories, or etymologies; illustrations; usage guidance; and examples in phrases or sentences. Dictionaries are most commonly found in the form of a book, but more and more dictionaries are produced as a software runs from electronic PDA or a general purpose computer. Most dictionaries are produced by lexicographers.

Data dictionaries
Coverage
Radio
Word order