Apparition is a magical method of transportation and is basically the magical action of travelling by having the user focus on a desired location in their mind, then disappear from their current location and instantly reappear at the desired location. It is by far the fastest way to get to one’s desired destination, but is tricky to pull off correctly and disastrous if botched up. Apparition is a very popular method of travel in the wizarding world, though brooms or portkeys may be preferred as the feeling of Apparition can be unpleasant to some.
A Licence to Apparate is required to practise Apparition legally. One must be at least seventeen (17) years old to obtain such a licence. Lessons in Apparition are available, for an additional charge, to students who are or will be of legal age when the next test is administered. Apparition is an optional twelve-week course offered at Hogwarts School of Witchcraft and Wizardry for, as its name suggests, learning how to Apparate. The class begins shortly after the Christmas holidays and is offered to students who are seventeen, or who will turn seventeen during the school year. The course costs 12 Galleons.
If you turn seventeen anywhere between September 01 and the end of school in June of your sixth year, you may take the class in January. But if you turn seventeen after the school year ends, then you have to take it in your seventh year if you wish to take it.