Fredkin gate

A Fredkin gate is like a machine that helps computers talk to each other. It takes in three inputs, and then it either switches one of them with another, or it leaves them the same. Think of it like a playground game of trading cards. You can trade one of your cards with another person, or keep it the same. The Fredkin gate does this with tiny computer parts called qubits, which help computers do really complicated things very quickly. So, if you imagine a big playground filled with lots of people trading cards, the Fredkin gate is like the teacher who helps them trade cards in a special way that makes it easy to do lots of them really quickly.