Length. (said the vicar to the duchess. :yes:)
A decent length breaker bar will allow you to put more force on a stubborn bolt than a ratchet will. The one I linked to is 15" long, which should allow you to undo virtually anything on your car. A rachet is about 8" long, breaker bar twice as long: lots more force at the pivot= Lesley doesn't rupture herself undoing tight bolts.
Hexs: If you look into a socket, most have twelve points inside to grip onto a bolt. 12point socket= multi hex. A six point socket has, you guess it, six sides, the same as a bolt, and grips firmer to the bolt. Pros and cons to each, I prefer multi hex for no valid reason.
Long sockets are, as you presumed, just that.
R