Why is scan scheduling also called elevator algorithm?

Scan scheduling is a disk scheduling algorithm.In this algorithm disk arm proceeds into a specific direction and responds to the requests coming on its way and after reaching at the end of the disk, it reverses direction and again responds to the request coming on its way. It works like an elevator and that is why it is also known as elevator algorithm.

the correct answer is "part of speech" if the portion used is "verb, noun" there is another question similar to this with the same question but different portion. the other portion is "hand write" and the correct component for that question is "antonym".

hope this . : )