Cover

Cover is an abstract term generally meaning giving closure and protection, and has several uses:

a cover can be a lid or seal, usually one that completely closes the object
Cover charge, an entry fee
Cover (telecommunications), a communications concealment technique
Cover (philately), generic term for envelope or package
Cover (law), a remedy for the breach of a contract for the receipt of goods.
Cover version, a new version of a previously recorded song
Cover band, a musical band that plays only cover versions
Cover (topology), the mathematical concept of a collection of subsets of a set whose union is the whole set
Cover (unit), an area approximately equal to 2698 square metres
Cover (military), a form of protection in combat
Cover (intelligence), the purported occupation or purpose of an agent.

See also