A license is a personal privilege to use the land of another. A license is not considered a true interest in the land because it is revocable at any time, and would not transfer with the title.
Examples of a license would include parking your car in a parking garage or a ticket to the movie theater. A license can be created with an oral agreement, such as giving someone permission to fish in your lake.
You are now getting your real estate license. Let's not forget why it is called a REAL ESTATE license. Real refers to REAL PROPERTY and ESTATE has to do with the duration of ownership.