Difference between acceptance test and functional test?

Question

What is the real difference between acceptance tests and functional tests?

What are the highlights or aims of each? Everywhere I read they are ambiguously similar.

Answer 1

They are the same thing.

Acceptance testing is performed on the completed system in as identical as possible to the real production/deployement environment before the system is deployed or delivered.

You can do acceptance testing in an automated manner, or manually.