Quick two part question on PCB manufacturing. I am looking to order a prototype PCB and all the manufactures I've gotten a quote from all offer to include a Laser stencil, some charge for the stencil some are given free with the board. After looking online to me it looks like the laser stencil just shows the outlines of the pads.
So 1. Why have a laser stencil? what advantages do you get from having one?
and 2. Why do some manufactures charge and some are free for what looks like the pad outline?