This chapter delves into the evolution and importance of employee engagement, tracing its origins back to the Second World War when the US Army recognized the need for soldiers' readiness. Over time, the concept has expanded to define the emotional attachment individuals feel towards their organization, significantly impacting their satisfaction and performance. The chapter explores various definitions, factors influencing engagement, and provides practical implications for organizations. It addresses contemporary challenges such as virtual engagement, aging workforces, and diversity and inclusion. By reviewing empirical research, the chapter offers insights for employers, practitioners, and researchers to enhance engagement, implement effective solutions, and explore new models. It highlights the distinction between engagement and job satisfaction, factors leading to engagement, and innovative practices. Additionally, it discusses the future of engagement, emphasizing flexibility, trust and technological integration. This comprehensive overview is essential for those aiming to foster a highly engaged and effective workforce.