When choosing a security camera you have several options. The Transmission Type for your Security & Surveillance Cameras is very important. This will determine what  wiring and security system you will use. Analog transmission type will allow you to use coax cable with analog cameras in an NTSC or PAL format. Analog cameras are still the most popular form of cameras in the world. Network IP transmission type will allow you to use CAT5e (network cable) to install your cameras. This type of camera is digital and offer you a megapixel image resolution that you cannot get with a typical analog system. The third option is that of HD-SDI. HD-SDI is a relatively new player in surveillance. It offer you the ability to also use coax cable like analog cameras but it also transmits megapixel video like that of IP cameras.