Peggy, Beta is a term used in general concerning software. It is a kind of "pre-release" of a software (and sometimes hardware--like a high-speed copier), where the software is sent to certain customers that essentially help debug and recommend minor improvements before the actual release of the software for sale.
Since I've been using AC beta versions, they tend to be very good. The betas that I've seen from AC don't "break" things that are already working and accepted-- AC apparently is pretty good at "alpha" testing the software.
Beta software is generally used by experienced and loyal customers that know what they are getting into with a beta and generally wont hold it against the manufacturer if it doesnt work quite as advertised.
If you are new to AC and/or just starting up, you should not use a beta version of the software.
