Here is a simple example of home automation which includes a weather station with a couple of outdoor sensors, surveillance camera, x10 devices such as indoor and outdoor switchers and dimmers. All this stuff is controlled via PC which run under Linux. Also, it uses HEYU – text-based console program for remotely controlling lights and appliances in the home.
This example may give you a general idea about what is the home automation. Moreover, you see that smarthome system can be as complicated as you need.