In common usage, a collection is any group of items that has one or more properties in common, usually brought together for some specific purpose. See Collecting and Collectibles.

The term can also be used more specifically:

• In finance, a collection agency is a business that pursues payments on debts owed by individuals or businesses.
• In literature, a collection is an anthology consisting of works by a single author.
• In mathematics, collection is not precisely defined, but can refer to various objects. Most often it refers to a set, class, family, or multiset.
• Collection in equestrianism describes a way in which horses move and hold themselves.
• In museums and art galleries, the collection of objects in a particular field forms the core basis for the museum.
• In music, specifically diatonic set theory, a collection is similar to a tone row; see generated collection.
• In a church, the collection is the money collected from the congregation during a service. The congregation normally place their donation into a collection plate, basket or bag, which is passed around and returned to the priest.
• At the University of Oxford, Collections are exams given by a student's college to determine their ongoing performance.