Used to amplify a signal or as an on/off switch. Is found is most modern electronic devices.The number of transistors that can be placed inexpensively on an integrated circuit doubles approximately every two years.

The statement you provided is describing a transistor. Transistors are semiconductor devices used to amplify or switch electronic signals and electrical power. They are an essential building block of modern electronic devices and are commonly used in applications such as signal amplification, regulation of electrical signals, and switching.

The second part of your statement is referring to Moore's Law. Moore's Law is the observation that the number of transistors on a microchip doubles approximately every two years, though the cost of computers is halved. This law, formulated by Gordon Moore in 1965, has held true for several decades and has been a major driving force of technological and social change, productivity, and economic growth.