that version control automatically deals with bugs?
Isn't it exactly what was said: when you detect a bug you can go back to earlier code that didn't have it. It's automatic, you don't have to find the bug at all. However I believe it's not that simple.
In theory - and there are systems that do this - you can automatically remove a bug if you combine `git bisect` with unit tests. I have never met anyone who had such a sophisticated setup but my linux magazine tells me some people do that.
What you do with git bisect, is you make a binary search for the one change which introduced the bug. You start by telling git the version number of the working code, and a version number for broken code. And git will interactively let you binary search through the versions in between until you find the one commit, which introduced the bug.
This is much more sophisticated then what you usually do. Even if you have SVN or CVS or whatever: step back in time, undo change after change, until you find a version which works; then look at what you changed... that's often 99% of finding a bug.