ever = at any time during the lifetime of (whatever the topic is) always = all the time, continuously, not changing

"ever" means "at any time". "always" means "all the time" . Ever is the contrary of never, when you put "ever" in a negative sentence it means never, the same doesn´t happen with always: I don´t ever agree with him= I never agree with him I don´t always agree with him= sometimes I agree and sometimes not In some cases "ever" can mean always, but in imperative or emphatic phrases and with some preposition like "as ever" or "forever".

'always' - at any time, never ending. 'ever' can have the same meaning as 'always' but then it is used in a more formal way, not for casual language. Other meanings of 'ever' are 'at any time' (used in negative sentences) and to emphasize something in a comparison (the best/worst ever). I hope this clarifies it a little.