Home security systems consist of indoor systems and outdoor systems.
Indoor home security systems are installed at your doors and windows. They work by checking for two things: opening of doors and windows, or signs of movement inside the house. The system detects the latter with the help of motion sensors.
The outdoor home security system also monitors your grounds. Most outdoor systems are programmed to turn on flood lights at the slightest hint of movement on your grounds.
Outdoor alarms also include driveway alarms to ensure the safety of your car.
Some of the more expensive and sophisticated home security systems offer you the added security of close-circuit television (CCTV) and wireless video surveillance (VSS). These generally consist of several transmitters and one receiver, which are connected to your TV or VCR.
The advantage with such wireless systems is that the only cable you use is the one that connects your receiver to your TV. Wired systems are more reliable than wireless ones.
If you live in an apartment building, you can also opt for special home security systems designed to be installed in multi-apartment premises.