Acceptance testing is a testing technique where the system is tested for acceptability. In this, we test that system has met the requirement specification or not. It's a validation type testing.

Various forms of Acceptance testing:

1) User acceptance testing: It is performed by user representative to check that system meets its business requirements and all the user requirements have met. It is conducted at both developer and client site.

2) Operational acceptance testing: It is a maintenance test carried out by the customer. sometimes called operational readiness testing.

• In this tester checks that the processes and procedures are in place to allow the system to be used and maintained.
• This can include checking:

# Back Facilities
# Procedure for disaster recovery
# Training for end users
# Maintenance procedures
# Data load and migration tasks
# Security procedures

3) Contract  Acceptance Testing: It is carried out for those applications where the testing is outsourced. In this, Criteria for an accepting system are documented and contracted. So testing was performed to check that these criteria have been met before the system is accepted.

# Compliance acceptance testing: It is carried out to determine whether the application is developed as per standard or not. In this, we test system or product meet governmental, legal or safety standards.
Examples: Banking and pharmaceutical industries.

4) Alpha and Beta Testing:

# Alpha testing is carried out to identify all possible error or bugs before  releasing the product to the public.It is conducted at the developer's site by internal team members like tester in presence of end user.

It can also be done by potential users or customers. 

# Beta testing is carried out by the real user in the 'real environment'. Direct feedback from customer plays an important role in this testing. This is also known as ‘field testing’.