If you fly much, you must have noticed that long yellow line to the gate that the pilot follows and then there is an exact spot he/she stops the plane so it can align with the jetbridge. The spots are different for different planes. And the person below who ushers in the plane helps the pilot pinpoint the spot by moving his/her arms. (starts from two arms widespread and then slowly puts them together as the plane advances such that just as the plane reaches the spot, the two arms are together pointing upwards).

Today, I got a view of the different spots on the line. Guess how many types of equipments pull up to a gate? I would have guessed about 7-10. I counted nearly 30 of them marked on the ground!!