A license is a permit to do something: you need a license to drive a car or fly a plane. Having license also means to have permission.
When you have a license, you have official permission to do something, like drive a car. Bars need a liquor license to serve alcohol. Doctors need a medical license to practice medicine. But you can also say people have license to do something, which means they're free to do it — like James Bond, who has license to kill.
