an adjective is a word that modifies or describes a noun. Near is often used to describe physical or metaphorical distance.
The neighbors are very near to each other.
He always keeps his wallet near to him.
She wanted to sleep near the fire.
sometimes 'near' can be used in a more figurative sense, especially as an adjective, to indicate closeness in terms of relationship or similarity, not just physical proximity. Avoid redundancy. Phrases like 'near proximity' are tautological since 'near' already implies proximity.
as a preposition, near can be used to refer to a close proximity, either literal or figurative, between two or more objects.
The restaurant is near the school.
We like to keep our acquaintances near at all times.
She drew near to the pond to get a better look.
an adverb is a word that modifies or describes a verb, another adverb, or an adjective. Near typically describes the manner and result of an action in regards to physical or metaphorical proximity.
He was near dead.
He stopped near, waiting for her to catch up.