SMT is used to make circuit boards. It's a part on a circuit board.
SMT is a Surface Mount Technology (short for surface mount technology), which is called surface mount or surface mount technology.
It is a circuit assembly technology in which surface assembly components without leads or short leads (SMC/SMD for short) are mounted on the surface of printed circuit board (PCB) or other substrates, and then soldered and assembled by reflow soldering or immersion soldering.