Emboss means to carve with a design. A silver tray might be embossed with your initials and wedding date. You might give your teacher a plaque with "World's Best Teacher" embossed under their name.
Embossing and engraving have similar effects––a raised surface. But embossing pushes the paper or metal up, working from behind, while engraving actually cuts into the surface, cutting away a bit of the media as it makes its mark.