A license is temporary permission to use another's land. A license is personal property, not real property.
A license is permission to do a particular act on another's property, usually on a non-exclusive basis. A license is personal property and is not an interest in the land itself.
A license is temporary and may be revoked by the owner at any time. A license terminates when the land is sold or at the landowner's death.
A farmer allows people to fish in his lake for $12 per day. The Corps of Engineers allows you to camp on Lake Lanier for $25 per night. Both of these land uses are licenses.