ELI5: how does quantum computing work

What is a quantum computer?

A quantum computer is a special machine that uses tiny particles following very strange rules to solve problems, different from regular computers that use regular electricity. [1] Regular computers think in 0s and 1s (like yes or no), but quantum computers use "qubits" that can be both at the same time, like a coin spinning in the air. [4]

Why is it different from regular computers?

Normal computers have to try one answer at a time, like checking each door in a huge house one by one. [3] Quantum computers can check many possibilities all at once because their qubits can be in multiple states at the same time. [4]

What makes it work?

Quantum computers use the strange rules of quantum physics - how tiny particles actually behave in the real world. [1] These particles can do special tricks like being in two places at once, which helps the computer find answers super fast. [4]

Why would we want one?

Quantum computers could solve really hard problems much faster than regular computers, like figuring out secret codes or discovering new medicines. [3] They work in ways that regular computers just can't do. [2]