Online Help
A reference program within most software programs that provides basic descriptions and instructions on how to use that software program.

OR Gate
A logic circuit that requires that any input must be in a high state (logic 1) to generate a high state output (logic 1).

Output Relay
A device that changes its state upon receiving a signal from a controller. Typically the state change prompts an action outside of the controller such as activating or inactivating a device.