The human brain integrates memory and processing together, weighs less than 3 lbs, occupies about a two-liter volume, and uses less power than a light bulb. It operates as a massively parallel distributed processor. It is event driven, that is, it reacts to things in its environment, uses little power when active and even less while resting. It is a reconfigurable, fault-tolerant learning system. It is excellent at pattern recognition and teasing out relationships.
From this article about Cognitive Computing.