What is the external auditory meatus, and is it the apparent inner opening or the inner hole that contains earwax, and is it necessary to trace the folds of this opening when performing ghusl?

The ear canal is the opening of the ear that cannot be washed, and it is sunnah to wipe it. As for what the finger reaches from the ear, that is considered external and must be washed. It is disliked to pour water into the ear due to the harm it may cause.