All initiating devices are either  manual or automatic. An example of a manual initiating device is a pull station. This device does not sense any condition on its own. It must be activated by a person.

automatic initiating devices such as smoke detectors. Heat detectors. and waterflow switches. These initiating devices directly sense some environmental condition or the condition of another system or component.

Initiating devices. can be categorized as being either a spot type or a line type

Initiating devices can also be categorized as being either restorable or nonrestorable