what does smd mean and why am i being told that?

SMD stands for Surface Mount Device. It is a term commonly used in electronics to refer to components that are mounted directly onto the surface of a printed circuit board (PCB), as opposed to being inserted into holes on the board.

If someone is telling you "SMD," they may be referring to a specific type of electronics component or technology, or they may be using it as an abbreviation for something else. It's best to ask for clarification in order to understand the context in which it is being used.