Transistors – The Invention That Changed The World

A transistor is a miniature semiconductor that regulates or controls current or voltage flow in addition amplifying and generating these electrical signals and acting as a switch/gate for them. Typically, transistors consist of three layers, or terminals, of a semiconductor material, each of which can carry a current.
When working as an amplifier, a transistor transforms a small input current into a bigger output current. As a switch, it can be in one of two distinct states — on or off — to control the flow of electronic signals through an electrical circuit or electronic device.
Austro-Hungarian physicist Julius Edgar Lilienfeld proposed the concept of a field-effect transistor in 1926, but it was not possible to actually construct a working device at that time. The first working device to be built was a point-contact transistor invented in 1947 by American physicists John Bardeen and Walter Brattain while working under William Shockley at Bell Labs.
On its own, a transistor has only one circuit element. But they used to create simple electronic switches in small quantities. And in large numbers, they can create microprocessors where millions of transistors are embedded into a single IC.
Nowadays, they are used in everything from computer memory chips, to smartphones, cameras, memory storage devices, and more.