What does the 'select(x,y,w) do?

Hello there, I’m new with Ruby and I’m trying to develop a web app. I’m
following an example from the book and they used ‘select( )’ with three
parameters…what exactly does ‘select ( )’ do? I’m trying to have a
scroll down button that will let me select one of the options. Is there
another way to accomplish this?

I will highly appreciate your help.

Thank you so much