"proche" is an adjective. (can take an 's')
"près" is an adverb. (invariable)
In some cases you can use both with the same meaning but in some case only one word is appropriate.
e.g.
La station-service la plus proche. (adjective mandatory)
Je suis proche de toi. (It can have two meanings : nearby like in the next sentence or close in relationship)
Je suis près de toi. (nearby)
La fin est proche. (adjective mandatory)
I can't tell you all the cases but there is a grammatical difference, we can't say that it' the same thing.