Many years ago there were only about five types of security cameras available in the security systems market. Today things have changed considerably. At one time there were only tube security cameras. Today all of the security cameras we use for closed circuit television (CCTV) use a special computer chip called a CCD. These security cameras are a lot more dependable than their tube counterparts, and produce a much better picture. These chip security cameras are much less expensive to produce as well. All of these factors have made the use of CCTV much more affordable and practical for a wider variety of applications than ever before.