Matched Collection is a term used to describe a group of items that have been collected together for a specific purpose. The term is often used in the context of collecting items of similar value, such as coins or stamps. The term can also be used to refer to a SET of items that have been collected together for a specific purpose, such as a collection of books or a SET of tools. The term SET is an acronym for 'Selected, Evaluated, and Tested, ' which is a process used to ensure that the items in a matched collection are of the highest quality.