A glossary is a list of terms in a particular domain of knowledge with the definitions for those terms. Traditionally, a glossary appears at the end a book and includes terms within that book which are either newly introduced or at least uncommon. A bilingual glossary is a list of terms in one language which are defined in a second language or glossed by synonyms (or at least near-synonyms) in another language. In a more general sense, a glossary contains explanations of concepts relevant to a certain field of study or action. In this sense, the term is contemporaneously related to ontology.