A beta version is basically a test version of a software program. The program has been written and the author(s) think that it is probably bug free, but they aren't 100% sure. So they release a test version. Sometimes the test version is open to the public, sometimes just to a select group.
In any event, if you download a pre-release or beta version of a program, keep in mind that, since it is a test version, you may encounter problems. These problems are generally isolated to the program, but it may accidentally cause damage to other software on your machine (especially shared files). So, beta test at your own risk!
For more information : Google / Alan [most probably he won't choi(response) you.]
