Air Traffic Control (ATC) controls the movements of aeroplanes near an airport. This is a very important job because if there is no communication, aeroplanes may crash into each other!
People who work at the ATC need to know the positions and speeds of different aeroplanes. Normally, the ATC communicates with several aeroplanes simultaneously.
It is very difficult to just look at different numbers for each aeroplane. Because there are so many aeroplanes, the ATC will get confused handling so many aeroplanes. So, what does it do? Let's find out!