Understanding version 2 install

Ok I am a little confused with beta,RC and stable. I have installed both and have seen in the stable I can upgrade to freepbx 12. Is this like going from stable to beta?

After doing the upgrade my version still appeared to be 5.211.65-16 but was on freepbx 12?

So what is the difference between upgrading stable to 12 or just using beta? If I upgrade stable to 12 could I use the next upgrade script?

thnx

You might be confusing installing the different versions of Asterisk with the different versions of FreePBX.