Hi Colleen thank you for your comment, an overlay is a paper that is transparent, is most times a png but can sometimes be a psp’s. they are usually a transparent pattern or an effect like adding smoke perhaps. If a pattern place it as a new layer over your chosen background layer, as an effect, place it over the element or sometimes under you are wanting the effect to show. It could be say lightening, which case you may need to place it several layers on top, so it enhances the picture in a larger area. Hope this explains it. ask if you need further info .
The bevel edge , which is what I think you are asking, is under Effects/3D/inner or outer bevel. emboss is on the side panel/ light and darken brush/ emboss