Logic gates are fundamental building blocks of digital circuits. In combination, they can be used to build large networks that performs complex operations -- like your computer. But how, exactly, do they work?
In the real world, logic gates tend to assume the form of transistors -- though in the past, they have been created using vacuum tubes, electromagnets and even pneumatic systems. Anyway, in this video, Professor Brailsford from the University of Nottingham, explains the theory behind how the gates work -- and why you should be so happy that they exist. [Numberphile]