Artificial intelligence, often just called "AI", is a term people use when talking about the creation of machines and computers that can think for themselves. The word "artificial" means something man made to be like nature.
Modern computers can only "think" what its creator tells it to. The goal with artificial intelligence is to create machines that can learn and think just like human beings. Many scientists and academics study and experiment with AI a lot, but there has never been a computer that have truly been pure artificial intelligence. But simple AI is already used in our society, like to tell enemies how to act in video games, or in the heavy industry to do repetitive and boring tasks that are too simple or degrading for humans to do for a living.