At the Wall Street Journal, MIT lecturer Irving Wladawsky-Berger explained that soft AI is "generally statistically oriented, computational intelligence methods for addressing complex problems based on the analysis of vast amounts of information using powerful computers and sophisticated algorithms, whose results exhibit qualities we tend to associate with human intelligence."
For most of us, soft AI is an everyday part of our lives. As Kurt Anderson at Vanity Fair notes, it allows us to refill prescriptions, cancel airline reservations, and obey the instructions coming from the GPS.
Then there's strong AI.
According to Wladawsky-Berger, strong AI is "a kind of artificial general intelligence that can successfully match or exceed human intelligence in cognitive tasks such as reasoning, planning, learning, vision and natural language conversations on any subject."
Some people think that this "mechanical general intelligence" is inevitable given the exponential rate at which technology advances.
You can see it in Moore's Law, named for Intel cofounder Gordon Moore.
http://www.businessinsider.com.au/when-artificial-intelligence-turns-scary-2015-5