In recent years, there has been a growing interest in the potential role that digital technologies can play in promoting well-being. Smartphones, wearable devices, virtual/augmented reality, social media, and the internet provide a wealth of useful tools and resources to support psychological interventions that facilitate positive emotions, resilience, personal growth, creativity, and social connectedness. Understanding the full extent of this potential, however, requires an interdisciplinary approach that integrates the scientific principles of well-being into the design of e-experiences that foster positive change. This book provides an overview of recent advances and future challenges in Positive Technology, an emergent field within human-computer interaction that seeks to understand how interactive technologies can be used in evidence-based well-being interventions. Its focus of analysis is two-fold: at the theoretical level, Positive Technology aims to develop conceptual frameworks and models for understanding how computers can be effectively used to help individuals achieve greater well-being. At the methodological and applied level, Positive Technology is concerned with the design, development, and validation of digital experiences that promote positive change through pleasure, flow, meaning, competence, and positive relationships.