^[down arrow] or ^ [up arrow] will move caret down or up in the editor

I saw this function-key in bottom of pop-up window in editor always when coding keyword of functions but tried many times in macbook to see what will happen. It is not really problem to use this editor.. but I am inquisitive what is the function used for? 

in fact, when I tried ^ [up arrow] then all of my windows are switched to dashboard view in mac system.

Thank you.