Overview of User Acceptance testing - what does it mean and what are its forms.

User Acceptance Testing is often the final step before rolling out the application. Usually the end users who will be using the applications test the application before ‘accepting’ the application.
A formal product evaluation performed by a customer as a condition of purchase. The testing can be based upon the User Requirements Specification to which the system should conform. Use Acceptance testing is black box testing.

USER : System developers cannot do it, as although they are expert in writing software, they are unlikely to know anything about the realities of running the organisation, other then what they have acquired from requirements specifications, and similar documents.

Acceptance : The acceptance of a system means you are confident it will give benefit to the organisation. It does not mean that it only meets the original specification as requested.

Testing : Whenever people are asked what testing is, many of them say it is to prove the system works.
The point of UAT is for business users to try and make a system fail, taking into account the real organisation it will be working in.

User Acceptance testing can be in the form of :
Alpha Testing - Tests are conducted at the development site by the end users. Environment can be controlled a little bit in this case.
Beta Testing - Tests are conducted at customer site and development team do not have any control on the test environment.