This textbook provides learners with an in-depth analysis of firms that operate as platform businesses. It introduces platform firms as unique business models. Leveraging the early literature on network economics and strategy frameworks, this text elucidates how platform business firms evolve in the modern business world. Taking a strategic perspective, it engages learners with core concepts, frameworks, and tools required to design and operate a platform business firm. Using case studies and analytical frameworks, the book (a) differentiates platform business firms from traditional pipeline firms; (b) explores engagement with different user-groups, value architecture (value creation, delivery, and capture), and operations of platforms; (c) elucidates resources and capabilities of platform firms that provide them with sustained competitive advantage; (d) analyzes performance levers in operating platform business models, including complementarities with other business models; and (e) discusses the sustainability of platform business models in the face of technological, regulatory, and societal challenges, among others. This edition is designed as a comprehensive textbook for graduate and post-graduate courses in technology, management, and policy programs, specifically focusing on platform business models, digital business strategy, new-age business models, technology strategy, and similar topics. An additional USP is that the book comes with an instructor manual, including slide decks and case teaching notes, available to instructors teaching the course.