The document discusses processes and process scheduling in operating systems. It defines a process as a program in execution that changes state as it runs. Process information is stored in a process control block. Processes move between ready, running, waiting, and terminated states. The operating system uses long-term and short-term schedulers to select which processes to move between queues like ready and device queues. Context switching occurs when the CPU switches between processes. Processes can cooperate through communication and synchronization using message passing or shared memory.

4. Diagram of Process State

6. Process Control Block (PCB)

7. CPU Switch From Process to Process

9. Ready Queue And Various I/O Device Queues

10. Representation of Process Scheduling

12. Addition of Medium Term Scheduling

17. Processes Tree on a UNIX System

34. Socket Communication

36. Execution of RPC

38. Marshalling Parameters