The major tech giants (e.g. Google, Amazon, Facebook, Microsoft, and Apple) are convinced that artificial intelligence (AI) will transform the world in short order. AI algorithms determine our internet search results. They recognize faces in our photos and identify commands spoken into our smartphones. They translate sentences from one language to another and can defeat the world champion at Go. They power self-driving cars and autonomous robots, drug discovery and genomics. In other words, the number of applications of AI technology is exploding. Investments in AI will also discover a new frontier for computing hardware, since many companies, from giant semiconductor companies to a myriad of startups, are racing to develop new AI-specific chips.

Modern AI technology is based on deep learning algorithms. These algorithms learn tasks on their own by analyzing a very large amount of data. To do so, they flow data through multiple processing layers, each of which extracts and refines information obtained from the previous layer. The "deep" in deep learning refers to the fact that these algorithms use a large number, say dozens or hundreds, of processing layers. This depth allows them to learn complex tasks.