There are two main types of home security systems, (DIY) do-it-yourself systems and professional systems (installed by a professional), which are installed by a company and usually provide monitored home security. DIY security systems are wireless systems that are often a lot cheaper quality and will not have customer support and know how like a professional system.

DIY systems can be purchased from most local hardware or home improvement stores, and can provide a great level of basic alarm functionality. They are much cheaper than they used to be, with many more choices and features available. Wireless systems start at as little as $200, and usually include a couple of door and window sensors and maybe one PIR motion detector, but do not include monitored security. With a DIY security system, you will have to expect that quality and effectiveness will not be anywhere near a  system that is professionally installed.

Wireless security systems are becoming extremely popular due to their flexibility, ease of installation and cost. Like a professionally installed alarm, a variety of sensors can be added to the system such as door/window sensors, PIR movement detection sensors, smoke detectors and carbon monoxide detectors.