Artificial intelligence refers to the ability of a computer system or machine to perform tasks normally requiring human intelligence. There are two categories of artificial intelligence. The first and most common is Weak AI, or Artificial Narrow Intelligence. Narrow Intelligence is focused on doing specific tasks and represents all existing AI systems. The second is Artificial General Intelligence (AGI) which represents the ability for a system to perform intellectual tasks (adaptable intellect) just as a human would. Such systems do not exist at the moment. In 2013 a consortium of scientists, researchers, and philosophers concluded that there is a 50% chance AGI would be developed between 2040 and 2050.