If you're licensed, you have official approval to do something, like drive, fly a plane, or be a physical-therapist assistant.
Lots of people need to be licensed before they can do their jobs: doctors, dentists, chiropractors, and even hairdressers have licenses. You have to be a licensed driver to get behind the wheel, and only a licensed pilot can fly a plane. However, there is no license required to have a child; therefore, you won't easily find a licensed parent.