Alpha Testing: Simulated or actual operational testing by potential users/customers or an independent test team at the developers’ site. Alpha testing is often employed for
off-the-shelf software as a form of internal acceptance testing, before the software goes to beta testing.
Beta Testing: Comes after alpha testing. Versions of the software, known as beta versions, are released to a limited audience outside of the company. The software is released to groups of people so that further testing can ensure the product has few faults or bugs. Sometimes, beta versions are made available to the open public to increase the feedback field to a maximal number of future users.
*Debugging: A methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware thus making it behave as expected. Debugging tends to be harder when various subsystems are tightly coupled, as changes in one may cause bugs to emerge in another.