This document outlines the units and topics covered in the II Year - I Semester course on Operating Systems. The five units cover an introduction to operating systems and their structure, processes and process scheduling, inter-process communication, memory management and virtual memory, deadlocks and file systems, and system protection and security. Key topics include operating system services, system calls, multithreaded programming, paging, virtual memory, deadlock detection and avoidance, and implementing security defenses like cryptography and firewalls. Example operating systems like Linux and Windows are also case studies. The course aims to explain fundamental operating system concepts.