What is (β) Beta release?

Have you ever wondered what does β (BETA) mean on most of the Google apps example ? Well beta is nothing but the fact that indicates that the software is not fully tested and is open for beta testing. This is one of the ways in which a company can protect itself if some serious issues start getting reported against there software (This is my thought)

A beta release can be open or closed. An open beta release is normally available to the general public to download and test. A closed beta release is available only to a specific group of beta testers.

So now you know at least what Beta indicates?