Transistor

The transistor is a semiconductor device used to amplify or switch electrical signals and power, and is one of the basic building blocks of modern electronics. It is built from semiconductor material with at least three terminals: a voltage or current applied to one pair of terminals controls the current that flows through another pair, which lets the device amplify a signal because the controlled output power can exceed the controlling input power. Some transistors are packaged individually, but far more are embedded in miniature form inside integrated circuits. Because transistors are the key active components in practically all modern electronics, they are widely regarded as one of the twentieth century's greatest inventions. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/