A BJT (Bipolar Junction Transistor) is a type of transistor that uses both electron and hole charge carriers for operation. It has three terminals: base, collector, and emitter. BJTs come in two types: NPN and PNP. They are used to amplify or switch electronic signals by controlling the flow of current between the collector and emitter, with a small current applied to the base. In an NPN transistor, current flows from the collector to the emitter, while in a PNP, it flows in the opposite direction. BJTs are widely used in analog circuits.
 NPN Transistor |
 PNP Transistor |