We kind of went over the basic types of handlesets there are in this post, but we can even break it down a little bit more. So as you already know, there are the basic single/double cylinder handlesets, double sided, two point locks, interconnected locks and mortise, but we didn't mention sectional, full length or monolithic. It's basically just the style of the handleset. They all work the same pretty much.

Sectional:

 width=     A sectional handleset is where the backplate of the deadbolt and thumb latch/handle are separated. These handlesets are good for doors that are not prepped the standard 5 1/2" cc bore (check out this post for more info on door prep) Some bore holes (holes in the door where the deadbolt and door handles go) are further away, and the sectional handlesets help with that problem, because the deadbolt and handle can be separated, where the monolithic or full length can not.    

Monolithic:

 width=     Monolithic has a full plate between the deadbolt and thumb latch. And unlike the sectional, You will have to do a few more measurements before you order. You will have to make sure that the CC prep (the measurement from the center of the deadbolt hole to the center of the hole where the handle goes, or center to center, standard is usually 5 1/2") is right on, or it may not fit. It's rare that this is a problem, most doors are prepped standard. It's better to be safe than sorry though.      

Full Length:

 width=     Full length goes hand in hand with monolithic, other than it has a full backplate all the way from the deadbolt to the bottom of the handle. Usually standard door prep just like the monolithic, but may be a little more spendy. I personally like this look best.         Never short on choices when choosing a handleset. The pictures shown are from Emtek, but you can check out all the styles here.