Qquantum computinguantum computing could change the world. It could transform medicine, break encryption and revolutionise communications and artificial intelligence. Companies like IBM, Microsoft and Google are racing to build reliable quantum computers. China has invested billions.

Recently, Google claimed that it had achieved quantum supremacy – the first time a quantum computer has outperformed a traditional one. But what is quantum computing? And how does it work?

What is quantum computing? Let’s start with the basics.