Light-emitting diodes are small devices used in many different applications, even for standard light bulbs. In recent years, LED SMTs have changed how we do many things. Surface Mount Technology LED lights have revolutionized how people do things at home, and made it easier for companies to do business. LED SMT (surface mount LED) is just another version of surface mount technology (SMT). Other SMT uses are through via-hole versions but are not as popular as surface mount.