I want to install Bitcoin Core on my system which I have newly formatted. I have done this several times before. Now, I am wondering which version to use.
The newest one is v0.14.2rc2 But what the hell does the rc2 mean?

Also, is it best practice to always install the newest version of core in terms of reliability and safety?

Is it possible to install a new version of core although there is already a core client with an older version installed?