This course provides an in-depth study of the principles, design, and implementation of modern operating systems. It examines the operating system as a resource manager and control program, focusing on process management, inter-process communication, concurrency, memory management, and scheduling. Advanced topics such as multiprogramming, time-sharing systems, virtual memory, and distributed and real-time operating systems are explored in detail. The course emphasizes both theoretical foundations and practical considerations, enabling students to analyze system performance, understand kernel-level mechanisms, and design efficient operating system components. By the end of the course, students will be equipped to critically evaluate operating system designs and apply OS concepts to advanced computing systems and research problems.