Z-Wave is a wireless protocol for devices to communicate with each other. Think of bluetooth wireless communication between your headset and your phone. But z-wave is different in that it is a mesh network. Very many devices can be on the network and a device can pass on messages meant for another (farther away) device. Also, mesh network can span a much bigger area by simply making sure that the distance between devices is not too great such that they can’t talk to their neighbor.

Z-Wave communicates using a low-power wireless technology designed specifically for remote control applications. The Z-Wave wireless protocol is optimized for reliable, low-latency communication of small data packets with data rates up to 100kbit/s(*1).

Z-Wave was developed by Zensys and Z-Command’s implementation is based on Zensys’ official SDK.

With regard to home automation, one obvious advantage is that sensors are wireless. This makes it really quick and simple to set up and expand home security systems with tens of sensors e.g. motion, door and window sensors.

Another not-so-obvious advantage of a z-wave home automation/security system is that you can have more than one wireless siren and they can be located in hard to reach places like the attic. So, even if an intruder stops one siren, 2 others could keep on screaming.

References:

(1) wikipedia.org