Gerry Baker is Editor at Large of The Wall Street Journal. His weekly column for the editorial page, “Free Expression,” appears in The Wall Street Journal each Tuesday. Mr. Baker is also host ...

At the simplest level, computers are little more than a collection of transistors and circuits. They connect together to form logic gates, which in turn are used to form logic circuits.

In this video, Jonny Nelson introduces an animated explanation of circuits and how they work. Electrical current transfers energy around circuits.