Demons like any entity have many names and titles. They live behind the veil and even the lower astral. By definition a demon is a being who tries to cloak your eyes from God. So even a human can be a demon. Demons are not to be considered as non human entities such as nature spirits although some of them are. Demon has been used as sort of a lump sum name for non human spirits by the spiritually illiterate.

So to simplify.
>there are spirits
They live lives just like us, but not like us as they aren’t human
>there are demons
Any being who promotes separation from God and tries to bring you away from good

The bad ones aren’t too eager to handout details about their names, hierarchy and who they serve.

Which leaves most of the demon name debate in the air and without enough data to solve. Luckily knowing a demons name is irrelevant as it’s best you don’t associate with them in any manner.