From The Art and Popular Culture Encyclopedia
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 of 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.
A core glossary is a simple glossary or defining dictionary which enables definition of other concepts, especially for newcomers to a language or field of study. It contains a small working vocabulary and definitions for important or frequently encountered concepts, usually including idioms or metaphors useful in a culture.