For successful release you also should clarify:
It happens so that acceptance testing may be a part of system testing, normally the last part that answers the product release questions.
Nevertheless, we differentiate it from regular system testing by the differences in bug fixing possibilities.
For example, in system testing, all main defects will be corrected before product release; at the same time in acceptance testing, the defects will not be corrected because of oncoming product release.
The bugs detected in acceptance testing will be operated with during post-release product support. In practical applications, critical bugs detected in acceptance testing could cause expensive protractions to pre-planned and usually pre-announced product release. The price of such protractions needs to be weighed against the price of delivering a product with main flaws, in order to arrive at a product release decision.
If we are talking about the testing techniques, the ones usable for system testing are all potentially usable for acceptance testing.