Artificial intelligence is the science and engineering of making intelligent machines, especially intelligent computer programs. There are four main schools of thought in AI: thinking humanly, thinking rationally, acting humanly, and acting rationally. Popular techniques used in AI include machine learning, deep learning, and natural language processing. The document then discusses the growth of AI and its applications in various domains like healthcare, law, education, and more. It also lists the top companies leading the development of AI like DeepMind, Google, Facebook, Microsoft, and others. Finally, it provides perspectives on the future impact and adoption of AI.