There’s a few distinct differences between embossing and debossing:
Emboss: The process of pressing an image or design into paper, so it lies above the surface of an already printed sheet, by an uninked block or die.
Deboss: This is essentially the opposite of embossing, where the image or design is pressed into the paper, so it lies below the surface of an already printed sheet, by an uninked block or die.
Blind Debossing: When an image is pushed down into the paper, below the surface. This leaves an indented texture into the paper.
Blind Emboss: When an image is raised up out of the paper without the use of ink or foils. This method is not recommended for intricate designs or detail.