What is artificial intelligence?

A computer can beat the world chess champion and understand voice commands on your smartphone, but real artificial intelligence has yet to arrive. The pace of change is quickening, though.

Some people say it will save humanity, even make us immortal.

Others say it could destroy us all.

But, the truth is, most of us don't really know what AI is.

Video production by Valery Eremenko

Intelligent Machines - a BBC News series looking at AI and robotics