Positive psychology is a scientific field focused on understanding and fostering the factors that allow individuals and communities to thrive. This branch of psychology emphasizes strengths, virtues, and factors that contribute to a fulfilling life. It diverges from traditional psychology by prioritizing well-being over pathology, aiming to enhance life satisfaction, happiness, and resilience. Key concepts include positive emotions, engagement, relationships, meaning, and accomplishment, collectively known as PERMA. Interventions often involve practices like gratitude journaling, strengths identification, and mindfulness. Positive psychology is applied in various settings, from schools to workplaces, promoting mental health and personal development. By focusing on what makes life worth living, positive psychology seeks to build a foundation for enduring happiness and well-being, advocating for a balanced view of human nature that acknowledges both challenges and potentials. This book discusses the fundamentals as well as modern approaches of positive psychology. Such selected concepts that redefine this area have been presented in this book. The book is appropriate for students seeking detailed information in this area as well as for experts.