Difference between Alpha Testing & Beta Testing

These are the testing done by the users. Once the developers have finished their own testing with the help of other professional developers, the software is ready for release to the public or to the intended users.
The stages usually followed are:

Alpha Testing – Developers usually choose the users who will try out the program. These users can be any potential users/customers or an independent test team who carry out the testing at developer's site. It is often tested on known users or even technology bloggers who can honestly give their opinion of the software. It is also the time where developers try to create scenarios for their software such as:

• Recovery – Developers will try recovering the software or the program in case it crashes.
• Security – Like all software, developers have to test the program for possible hacks and virus infections.
• Performance – Use it extensively by getting more than one users to exhaust all possible options and see if the software will hold up to expectations.

Beta Testing – This type of testing is more open to the public and  is done outside the developer's site. Developers or software companies can accept users sometimes by invitation or openly accepting users. Beta testing is tested in a real environment where there is a bigger possibility of hacks, lack of performance or bugs. The main reason the software is given to the public for testing is to open it for possible hacks and feedback about the software. If something wrong is found, developers can just go back to the software easily. Versions of software that is given for beta testing are known as Beta Versions.