A more thorough explanation:

Alpha testing is the first phase of testing a software program before it is released to the public. This testing is usually done at the developer's site and involves testing individual components of the program.

For example, if a software program has different modules, alpha testing would involve testing each module separately to ensure that it works as intended. This testing is done to catch any bugs or issues before the program is released to the public.

Alpha testing is usually followed by beta testing, which involves testing the entire system at a customer's site. Beta testing is done to ensure that the program works in a real-world environment and to catch any issues that were not caught during alpha testing.