Distributed operating systems share many features with centralized ones but differ in key aspects. This paper introduces distributed operating systems and current research in the field. It discusses design issues and presents examples of research projects like the Cambridge Distributed Computing System, Amoeba, V, and Eden. Categories include distributed systems, file systems, reliability, security, and more. The introduction highlights the importance of distributed systems and their distinction from computer networks. A distributed system appears as a single machine to users but runs on multiple CPUs. Transparency is key, making the system seem like a single processor. The paper contrasts distributed systems with network operating systems, which are more hardware-based. It discusses design issues such as communication, naming, resource management, fault tolerance, and services. Examples include the Sun Network File System, which allows remote file access. The paper also covers communication primitives, remote procedure calls, error handling, and implementation challenges. It emphasizes the importance of efficient message passing and the complexities of ensuring reliability and correctness in distributed systems.Distributed operating systems share many features with centralized ones but differ in key aspects. This paper introduces distributed operating systems and current research in the field. It discusses design issues and presents examples of research projects like the Cambridge Distributed Computing System, Amoeba, V, and Eden. Categories include distributed systems, file systems, reliability, security, and more. The introduction highlights the importance of distributed systems and their distinction from computer networks. A distributed system appears as a single machine to users but runs on multiple CPUs. Transparency is key, making the system seem like a single processor. The paper contrasts distributed systems with network operating systems, which are more hardware-based. It discusses design issues such as communication, naming, resource management, fault tolerance, and services. Examples include the Sun Network File System, which allows remote file access. The paper also covers communication primitives, remote procedure calls, error handling, and implementation challenges. It emphasizes the importance of efficient message passing and the complexities of ensuring reliability and correctness in distributed systems.