A licence lets you do something that other people without a licence can’t do. For example, a driver licence is a card or paper from the government that says you can drive. It says the kind of car, motorbike or truck that you can drive. You can use the licence until the expiry date. After the expiry date you need to renew it.
A gun licence (also called a firearm licence) is a card or paper from the Government that says you can use a gun. It says the kind of gun you can use and where you can use it.