Most locks generally fall into one of five regularly encountered categories.  Then within each category you can find examples of different sub-categories and mechanisms that are operated by a key.  This article will look at the different categories of locks.  You can find out more about each type in separate articles about each kind.

The Mortise Lock

Installed in a mortise or pocket in the edge of the door.

The Rim Lock

Installed on the surface of a door, there are many designs available.

The Bored Lock

Installed via a cross bore and an edge bore.  Two sub types are known as Cylindrical and Tubular, and there are further devisions below that of Knob, Lever and Deadbolt.

The Interconnected Lock

Uusually a combination Deadbolt and Knob or Lever with a single trim plate and simultaneous operation.

The Pre-Assembled Lock

Usually only available as a Commercial grade product and typically requires a C shaped cut out in the door to mount it.  It also may be a Knob, Lever or Deadbolt.