Explainer: What is artificial intelligence?

Artificial intelligence has jumped from sci-fi movie plots into mainstream news headlines in just a couple of years. And the headlines are often contradictory. AI is either a technological leap into greater prosperity or mass unemployment; it will either be our most valuable servant or terrifying master. But what is AI, how does it work, and what are the benefits and the concerns? AI is a computer system that can do tasks that humans need intelligence to do. "An intelligent computer system could be as simple as a program that plays chess or as complex as a driverless car," Mary-Anne Williams, professor of social robotics at the University of Technology, Sydney, said.