NPN

An NPN is a type of transistor, which is a device that controls electrical current. It consists of three parts: two negatively charged layers (N) separated by a positively charged layer (P). When a small current is applied to the middle layer (the base), it allows a larger current to flow between the other two layers (the collector and emitter). This feature makes NPN transistors useful for switching and amplifying signals in electronic circuits. They are fundamental components in devices such as computers, radios, and power supplies.