Digital CCTV
Digital CCTV represents most new installations. These include conventional wired systems (coax), networked or IP cameras (Cat 5) and wireless, whether Radio, Microwave or WIFI.
The recording device is most commonly a DVR. A DVR can record up to 25 IPS (Images Per Second) based on Permanent Recording, Motion Detection(Movement), Alarm activation or a combination of all these.
The DVR can record on a standalone basis or can be connected to the IP Network. This offers huge flexibility and the option to view Live or Recorded images. If the DVR is connected to the IP Network - LAN or WAN - the user can view cameras, control PTZ (Pan, Tilt, Zoom) cameras and administer the system from their computer whether they are in the next room, next building, city or country. Many systems are seen as a Management Tool as much as a security system.
Cameras come in many shapes and sizes, dependant on the use and functionality. Here are some typical camera options;
Discreet dome camera
Used when the client wants to view an area without being too obtrusive or where there may be a risk of the camera being attacked. These cameras can be Vandal proof if required.
Covert camera 
As the name suggests, used to view an area un-noticed. There needs to be careful thought when deploying these types of cameras to avoid potential mis-use. Styles range from Clocks, Junction Boxes, Smoke detectors and Room Thermostats as shown. These cameras can be concealed in almost anything, if used properly.
Typical external Camera 
Very common sight. This image is of a standard external camera housing as seen in most applications. It houses the camera and lens and is usually fitted with a heater element to keep the viewing window clear in very cold weather.
External PTZ Dome
The high speed Dome camera allows the user to turn the camera and zoom into an inc
ident. This is a very powerful and flexible camera. They are best used when controlled by an operator to follow a person or incident over a wide area. They are now commonly used in larger commercial environments and especially in shopping malls.
These are just some of the options available.