Based on your needs and recording environment, you should select a camera that is best for you:
wired: a standard wired color security camera. Most wired security cameras today are indoor/outdoor and have an IR (infrared) cut-filter for night vision (the night vision image will be in black & white for improved contrast and image detail). Wired cameras are available in BNC or DIN terminations (connection ports) and will require video extension cables.
wireless: More and more people are turning to wireless cameras as a cost-effective way of building a comprehensive surveillance system in their home or business. The latest digital wireless cameras are secure, free of interference from household devices, and offer crystal clear video and audio.
IP / network: IP (Internet protocol), or network cameras are another option. These cameras connect to your computer’s router just like a computer or other net-workable device. IP network cameras allow you to access the cameras from remote locations over the Internet. Many also give you the option of recording video directly to your computer or to a network video recorder (NVR).

CCTV security cameras produce images using CMOS or CCD (Charge Couple Device) chips. Tiny and/or very low price CCTV cameras usually use CMOS technology, produce poor quality video and have very poor light sensitivity. Decent quality and better CCTV cameras use CCD technology. The size of the CCD chip is normally 1/4″, 1/3″ or 1/2″. As a rule of thumb, the larger the size, the higher the quality of the image produced and the higher the price. However, higher density 1/4″ and 1/3″ CCD chips can now produce as good an image as many older 1/3″ or 1/2″ chips.

If you are going to use the cameras in an environment where the light conditions are very low, it is recommended to buy a black and white CCTV camera system. Color should only be considered for inside use with good lighting conditions. For consumer-grade CCTV cameras, color cameras are suitable for indoor or outdoor applications. Many high resolution color cameras now use an IR cut-filter for built-in night vision.

One of the most important specifications. Light levels are measured in Lux. The lower the number, the less light it will take to reproduce a clear image.

The higher the resolution number, the sharper the image will be. Entry level camera resolution is 330 lines, high resolution cameras producing better than 400 lines.

Choosing the right monitor is really important to be able covering all CCTV cameras resolutions, heading to right sizes will give you the ability to visualize all the building for your security purpose.