Dude os.pullEvent()

I copied this code to study it, and I can not understand the width of the mouse as it affects the event of touching a monitor

event,p1,p2,p3 = os.pullEvent()
  -- this line tells the computer to wait until
  -- an event happens. We are waiting for a
  -- touchscreen event
  
   if event=="monitor_touch" then
   -- this checks to see if the event was a
   -- touchscreen event
  
	 mouseWidth = p2 -- sets mouseWidth
	 mouseHeight = p3 -- and mouseHeight 

http://www.computercraft.info/wiki/Os.pullEvent

http://www.computercraft.info/wiki/Monitor_touch_(event)

os.pullEvent() returns a sequence of values which depend on the type of event first found at the front of the event queue. If that's a monitor_touch event, then the first value is "monitor_touch", the second is the name of the peripheral it came from, and then come the x/y co-ords of the touch as the third and fourth values.

This snippet simply assigns those x/y co-ords to variables called mouseWidth and mouseHeight.