How come the Elite Four is Called that even though theres 5 people in the elite four?

Question

It's all in the title

Answer 1

Only four of those people actually make up the Elite 4.
The other person is the Champion, who is pretty much the most powerful person in the region. They were able to not only beat the Elite 4, but also beat the previous champion (except in the case of Alder, who was asked to be Champion.)
However, the Champion, while not being part of the Elite 4, is considered to lead the Elite 4. So I can understand the confusion.

Comments

Thank you for clearing my confusion.

Answer 2

There are four members of the Elite Four, one Champion. The Champion is not part of the Elite Four; hence the fact you can fight him/her after you beat the Elite Four indicating the the Champion themselves is not part of the Elite Four.

Answer 3

It's because the elite four are the ones in the four rooms, the fifth one is the champion which is technically not part of the elite four. Hopes this helps!