What does this particular access right mean exactly?"
What does that access right mean/do exactly?
Most access rights are pretty self-explanatory, but a few are named something cryptic that is not very descriptive of what they do.
All of the access rights are described in the StarTeam Administrator"s Guide. The best way to learn what all these do is to study this guide and try them out in a test server. This will help the Administrator decide what access rights should be assigned to the user base.