A driver's license is a card showing that you are qualified to drive because you have passed a driving test.
[US]regional note: in BRIT, use driving licence
driver's license in British English
(ˈdraɪvəz ˈlaɪsəns)
noun
US
(in the United States) an official document, certificate or card that shows that you are qualified and authorized to drive, having passed your driving test