The verb license or grant licence means to give permission. The noun license (American English) or licence (British English, Indian English, Canadian English, Australian English) refers to that permission as well as to the document recording that permission.

A license may be granted by a party ("licensor") to another party ("licensee") as an element of an agreement between those parties. A shorthand definition of a license is "an authorization (by the licensor) to use the licensed material (by the licensee)."

In particular a license may be issued by authorities, to allow an activity that would otherwise be forbidden. It may require paying a fee and/or proving a capability. The requirement may also serve to keep the authorities informed on a type of activity, and to give them the opportunity to set conditions and limitations.

A licensor may grant a license under intellectual property laws to authorize a use (such as copying software or using a (patented) invention) to a licensee, sparing the licensee from a claim of infringement brought by the licensor. A license under intellectual property commonly has several component parts beyond the grant itself, including a term, territory, renewal provisions, and other limitations deemed vital to the licensor.