Zigbee modules are a form of short range, low-power and low-data-rate wide-area networking communications protocol based on the IEEE 802.15.4 standard. This low power, low cost, and low data rate makes them ideal for battery powered applications, providing the necessary features of a reliable wireless link where line of sight is not available. They are used in a wide range of applications, including home automation, smart meters, medical devices, industrial monitoring, and more. They can be used in a mesh configuration, where each device has both a transmitter and receiver, and can also act as a light-weight packet router, relaying signals from one device to another. Zigbee is a robust and reliable communications technology, making it an attractive choice for wireless links in a broad range of applications.