Chapter 1 introduces collective intelligence (CI) as an academic concept. At a basic level, CI extends the conception of intelligence from an individual to a group level. Pierre Lévy formulated the modern version in 1994, when he described the invention of the Internet as a new universally distributed intelligence. Today, CI covers many different areas, but most definitions are vague and inconsistent across academic disciplines. Studies address collective problem solving in both small and large groups. At a micro level, researchers have identified a general group intelligence factor that is relevant for performance in small groups. At a macro level, studies of large groups have focused on different types of self-organization, including both stigmergy and swarm coordination. In addition, diversity examines CI as a core feature, both from the perspective of the “many wrongs principle” and the “many eyes principle.” Furthermore, the chapter provides a description of the book’s theoretical approach, building on Vygotsky and the inclusion of both biological and cultural-historical perspectives. The section on the methodological approach explains the data collection process, and the use of top solver perceptions of their participation in online innovation contests.