The document discusses 5 types of operating systems: simple batch systems, multi-programming systems, real-time systems, multi-processor systems, and distributed systems. Simple batch systems execute jobs in batches when the computer is idle. Multi-programming systems allow for more than one program to reside in memory at a time, improving CPU utilization. Real-time systems ensure processes are completed within a certain time frame and are used in applications like air traffic control. Multi-processor systems use multiple CPUs to improve performance. Distributed systems leverage networked computers to increase computing power and availability.