Ever means ‘at any time’. It is mainly used in questions. In affirmative sentences we use always and in negative sentences we use never.

Compare:

Have you ever been to the US on holiday? (= at any time.)

We always go to the US on holiday. (= every time)
We never have holidays in the US. (= at no time)

Ever does not mean always.

I will always love you. (NOT I will ever love you.)

In some compound expressions, however, ever is sometimes used to mean always.

his ever-loving mother
evergreen grass

Ever also means always in forever, ever since and similar expressions.

I have loved you ever since I met you.

Ever is used mostly in questions. It is also used in negative sentences, but never is more usual than not ever.

I never want to talk to you again. (More natural than ‘I don’t ever want to talk to you again.)

Ever is also used after words expressing negative ideas (like nobody, hardly).

Nobody ever helps me.
We hardly ever visit them.

Ever is common in affirmative clauses after superlatives.

What is the best film you have ever seen?

Ever with a present perfect tense

When ever is used with a present perfect tense, it means ‘any time up to now’.

Have you ever been to Italy?

When used with a past perfect tense, ever means ‘at any time up to then’.

The expression ‘than ever’ is common after comparatives.

She looked better than ever.

Ever and before

Ever and before have related meanings. There are, nevertheless, some differences. Before is used to ask if something has happened before. It refers to the present. Ever does not refer to the present.

Have you been to India before? (The listener is probably in India.)
Have you ever been to India? (The listener is not in India.)