This comprehensive guide explores the ITIL service lifecycle, a framework for managing IT services. It delves into the five key stages: service strategy, service design, service transition, service operation, and continual service improvement. Each stage is examined in detail, outlining its objectives, benefits, and processes. The guide also provides practical examples of how ITIL can be applied in various organizational contexts, including student enrollment services. By understanding the ITIL service lifecycle, organizations can optimize their IT service delivery, enhance customer satisfaction, and achieve their business goals.