Cylindrical vs Mortise Locks

Baldwin Hardware manufactures two types of entrance sets. The Images product line is a cylindrical type and the Estates is a mortise type. Cylindrical locks slide into the door through cylindrical holes that are bored through the face of the door, while mortise lock are inserted into the door via a large retangular hole that is machined into the edge of the door. A typical mortise locks is show below as an exploded view.

Mortise Lock
Exploded Mortise Lock