BETA ? what is it

I'm young but not stupid.
Can you explain what a " beta " download is , why i should take it or not.
I'm on Vista.
Thanks for your help.
/Stephanie

It means that the software is not in it's final form so it may have some bugs in it still.
If you can get info on what the known bugs are and if they are minor and acceptable to you then go ahead and use it, otherwise wait for the offical released version.

http://en.wikipedia.org/wiki/Beta_test#Beta