How do transistors function in an electrical circuit?

Transistors play a crucial role in electrical circuits by controlling the flow of current. The core function of a transistor is to act as a switch or amplifier. When it is used as a switch, a small input current at the base terminal of the transistor can control a much larger current flowing from the collector to the emitter. This property allows transistors to manage and regulate electrical signals and power efficiently.

By allowing a small current to control a large current, transistors become essential components in various applications, including amplifiers, where they can enhance the power of electrical signals. This ability to control and manipulate current makes transistors foundational elements in modern electronic devices, enabling their function in complex circuits.