Traditional wireless CCTV cameras are cheap but anyone with a wireless receiver can view your signal. On the other hand, IP cameras are secure but they can be quite expensive and usually the video quality is poor — unless you go for a really expensive model.
Lately I wanted to install a home surveillance system so I chose to use a cheap Logitech webcam with Raspberry Pi and motion, an excellent linux program that monitors video signal for changes and triggers events.
Full article here:
How to make a DIY home alarm system with a raspberry pi and a webcam (medium.com)