Practically, however, there are three main AI techniques that are proving useful today. There is supervised learning, in which an algorithm is given historical data inputs and outputs, and learns to predict outputs for those inputs. There is unsupervised learning, in which an AI system finds patterns for itself: for example, identifying groups of visitors to your site, without any clear distinctions about what defines a'group' from the outset. Games are a great example of this: give a reinforcement AI the rules of the game, and what defines'winning', and it will iterate until it has developed a strategy that'wins' according to those rules. We cover types of machine learning in more detail on our blog.