As is the video in a CCTV?

Video movies are not streaming images, but are a series of images that flash at a rate of 50 (PAL) or 60 (NTSC) fields per second with a time of space between each. These are even and odd fields and their combination is what we call boxes.
How a CCTV?

We assemble the equipment based on the most basic premise is simple and its main components,

CHAMBER
CABLE
MONITOR

From there we can design our system by adding the accessories you need according to customer requirements and safety criteria used, for example.

SEQUENCER
Quadrupled SCREEN
MULTIPLEXERS
LENS
DRIVERS
PAN PAN OR UNITS AND CABEZEO
GUARDS
VCR
VIDEO TRANSMISSION SYSTEMS (wireless, Phone, etc)

Then we will describe these teams with more depth.
What the CCTV security?

The CCTV will allow us to make identifications during or after the event you are viewing. It is therefore very important to define what role they will meet and where the cameras are placed, they must support the three types of identification:

Personal: This refers to the ability of the viewer to personally identify someone or something. (Faces, boxes, etc.)
Action: this interact much with the previous one and should be allowed to verify that an event actually happened. (Movements)
Scene: You must be able to identify a place in another similar location.

As the cameras should be selected?

The cameras should be selected according to three criteria

Sensitivity refers to the actual amount of visible or infrared light needed to produce a quality image.
Resolution: Sets the image quality from a particular perspective or reproduction.
Features: are settings that give extra edge over other cameras.

How to design a CCTV system?

It must take into account seven steps for proper design:

Determine the purpose of the CCTV system, and write a simple paragraph with the purpose of each camera in the system.
Define the areas that each camera view.
Choose the appropriate lens for each camera.
Determine where to locate the monitor or monitors to view the system.
Determine the best method for transmitting the video signal from camera to monitor.
Designing the control area.
Choose equipment based on system design notes.