An implied license is an unwritten license which permits a party (the licensee) to do something that would normally require the express permission of another party (the licensor). Implied licenses may arise by operation of law from actions by the licensor which lead the licensee to believe that it has the necessary permission.
Implied licenses often arise where the licensee has purchased a physical embodiment of some intellectual property belonging to the licensor, or has paid for its creation, but has not obtained permission to use the intellectual property.