Home Automation (HA) is the concept of using devices to make living in your home easier. For instance your home automation system will likely track your movements in your house (through motion sensors, or perhaps RFID), and turn lights on and off as you move from room to room. Ideally, it would alert you of email and phone messages awaiting your response. You could select music to be played for you, or a tv show to watch, and as you move about the music or show would follow you.

It would also be nice if your home greeted you when you entered with pending messages. It could keep each room in the house at the perfect temperature. It can detect problems in the house (fumes, significant heat loss/gain due to open window/door, etc) and could contain such problems by closing off ducts leading to problem areas. It could handle house security, notifying you of intruders. It would also freak the intruders out as the lights went on and off as they moved around. It can handle EVERYTHING for you.

Of course electronics hobbyists have better HA systems than you. I know I do.