Honeywell modules are devices that are used to expand the functionality of Honeywell systems. They come in a variety of types, including:

• I/O modules: These modules provide input and output connections for sensors and actuators.
• Zone modules: These modules are used to interface with fire alarm zones.
• Control modules: These modules provide additional control capabilities, such as relay outputs and timers.
• System modules: These modules provide additional system functionality, such as communication interfaces and network connections.