What is a Transistor

 A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be much larger than the controlling (input) power, the transistor provides amplification of a signal.

The history of the transistor dates back to the 1920s when semiconductor research began. The first transistors were created in 1947 by William Shockley, John Bardeen, and Walter Brattain at Bell Labs. They were made from a material called germanium. These early transistors were point-contact transistors, which were made from two closely spaced metal contacts that were placed on a germanium crystal. In 1951, the bipolar junction transistor (BJT) was invented at Bell labs. This type of transistor allowed for more reliable operation and higher performance than its predecessor. Further advances in transistors such as the Metal Oxide Semiconductor Field Effect Transistor (MOSFET) in 1959 led to the development of integrated circuits in the 1960s. The MOSFET was much smaller than