1. Narrow AI does one thing really well. Apple’s Siri, IBM’s Watson, and Google’s AlphaGo are all examples of Narrow AI. Narrow AI is fairly common in the world today.

2. General AI is a theoretical form of AI that performs most intellectual tasks on par with a human. Examples from popular movies might include HAL from “2001: A Space Odyssey” or J.A.R.V.I.S. from “Iron Man.” Many researchers are currently working on developing general AI.

3. Super AI, which is also still theoretical, has intellectual capacities that far outstrip those of humans. This kind of artificial intelligence is not yet close to becoming a reality.

Another popular classification uses four different categories:

1. Reactive machines take an input and deliver an output, but they do not have any memory or learn from past experience. The bots you can play against in many video games are good examples of reactive machines.

2. Limited memory machines can look a little way back into the past. Many of the vehicles on the road today have advanced safety features that would fall into this category. For example, if your car issues a backup warning when a vehicle or person is about to pass behind your car, it is using a limited set of historical data to come to conclusions and deliver outputs.

3. Theory of mind machines are aware that human beings and other entities exist and have their own independent motivations. Most researchers agree that this kind of AI has not yet been developed, and some researchers say that we should not attempt to do so.

4. Self-aware machines are aware of their own existence and identities. Although a few researchers claim that self-aware AI exists today, only a handful of people share this opinion. Developing self-aware AI is highly controversial.