Terminology is a group of specialized words and respective meanings in a particular field, and also the study of such terms and their use; the latter meaning is also known as terminology science. A term is a word, compound word, or multi-word expressions that in specific contexts is given specific meanings—these may deviate from the meanings the same words have in other contexts and in everyday language. Terminology is a discipline that studies, among other things, the development of such terms and their interrelationships within a specialized domain. Terminology differs from lexicography, as it involves the study of concepts, conceptual systems and their labels (terms), whereas lexicography studies words and their meanings.

Terminology is a discipline that systematically studies the "labelling or designating of concepts" particular to one or more subject fields or domains of human activity. It does this through the research and analysis of terms in context for the purpose of documenting and promoting consistent usage. Terminology can be limited to one or more languages (for example, "multilingual terminology" and "bilingual terminology"), or may have an interdisciplinarity focus on the use of terms in different fields.