What type of camera system should I get?
There are three main types of camera systems available on the market today. The most common one is an IP camera system, which uses an ethernet cable, which is the same type of cable that connects a computer to a router. The second type uses a coax TV type cable, and the third type uses a wireless network.
I recommend using an IP camera system in most situations where more than 3 cameras are needed. A wireless camera system with more than two or three cameras will use a lot of internet bandwidth. Wifi cameras are also more difficult to work with because they are going to require expensive batteries, solar panels, or have to have a power outlet near every place you want to put the camera. A coax system is sometimes cheaper, but it requires more cables because it uses a separate power supply. An IP camera is powered by a single data cable that also carries the power. All it needs is a switch that is capable of providing power over ethernet, or POE for short.