CCTV stands for closed-circuit television and is commonly known as video surveillance. 

This is a closed-circuit system because the signal is not openly transmitted as it is with broadcast television. The video cameras transmit the footage back to a set number of monitors

This technology dates a way back to the First World War.

The first CCTV camera was invented by Walter Bruch, a German tech enthusiast who wanted to observe how rockets are launched.

This war time technology was quickly adopted by the US government, and those surveillance cameras allowed them to observe nuclear bomb testing from a comfortable distance.

The development even allowed them to learn about the effects of nuclear weapons so as to avoid the dangerous effects that come afterwards.

The following years, public buses started using this CCTV to ensure the safety of passengers.

As of today, the video footages are also used to investigate incidents of robberies, assaults and car crashes among others.