What is a transistor?

Invented in 1947 at Bell Labs by John Bardeen, Walter Brattain, and William Shockley, the transistor replaced bulkier vacuum tubes in most electronics. It became the foundation of modern computing, mobile phones, radios, and countless other devices because it is small, reliable, and energy-efficient. Transistors are built into integrated circuits, where billions can fit on a single chip. Their invention helped launch the digital age and earned the 1956 Nobel Prize in Physics for the inventors.