SMD LED stands for surface mount LED. Specifically, it's a light-emitting diode that is mounted onto and soldered onto a circuit board. An SMD LED is quite small since it has no leads or surrounding packaging that comes with a standard LED. SMD LED also has a wide viewing angle, thanks to the fact that it does not have the standard LED's epoxy enclosure that focuses the beam. The SMD LED gives off very little heat. It also has a low voltage and current requirements. Like a standard light emitting diode, a surface mount LED gives off almost no heat. It also typically has similar low voltage and low current requirements.