INSTEON and X-10 are standards for communicating over normal home wiring in order to control devices, such as lamps and appliances. In addition to the home wiring, they can also communicate wirelessly. There are other standards as well, but no other home automation standard has the same, broad selection of affordable products.

INSTEON is the newer standard. Created by Smarthome Labs, it is generally more reliable and more capable than X-10. The product choices are already diverse and more options are being developed all the time.

X-10 was the first such standard to gain widespread adoption. Virtually every imaginable device can be automated with some kind of X-10 gadget. It is the most affordable product line, although you’re more likely to need a signal repeater or noise filters to get reliable operation throughout the home.

Here is an example of how they are used: Let’s say you have a lamp that you want turned off each night at 11:00 PM. You would plug the lamp into a lamp module and plug the lamp module into a wall outlet. This way, the lamp module can supply or deny power to the lamp itself.

Your PowerLinc V2 or ActiveHome Pro controller is plugged into an outlet near your Mac. Thinking Home, running on your Mac, will tell the controller to turn off the lamp at 11:00 PM each day and the controller will send a signal over your home wiring. The lamp module “hears” the signal and turns off the power to the lamp.