This introduction seeks to equip a diversity of policymakers with the core concepts needed to identify, understand, and solve artificial intelligence (AI) policy challenges. AI is best conceived as an often ill-defined goal, not a monolithic general-purpose technology, driven by a diverse and ever evolving constellation of input technologies. The document first introduces a sample of AI-related challenges to ground the importance of understanding this technology, the diversity of issues it will create, and its potential to transform law and policy. Next it introduces AI, key terms such as machine learning, and ways that AI progress can be assessed. Finally, it introduces and explains how three key input technologies— data, microchips, and algorithms—work and make AI possible. These core technologies are known as the AI triad. Intended to serve a variety of audiences, these explanations are presented with multiple levels of depth. Technical concepts are tied to relevant policy questions, thereby guiding the application of this knowledge while illustrating the value of understanding this emerging technology beyond a surface level. This introduction to AI appears both in written form and as an ever evolving website supported by the Mercatus Center.