This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book analyzes algorithms as epistemic devices, geared toward creating knowledge, which informs users’ decisions, preferences, tastes, and actions, and changes the very sense of who they are. It proposes to think about algorithms as epistemic devices, socio-technical assemblages engaged in the creation of knowledge about the world and about the self. The book then offers a reading of The Selfish Ledger, a short video created by Google, as a vignette through which to contemplate the ontology of knowledge in the age of big data, algorithms, and artificial intelligence. It also focuses on recommendation engines and seeks to clarify how the very notion of culture changes as algorithms take part in helping individuals make their own judgments of taste. The book details a concrete example of how algorithms are already becoming independent agents in the formation of the social and political life.