Operating System - What is PCB in Operating Systems

PCB stands for Process Control Block.

It is a data structure maintained by the operating system for every process. The PCB stores all the information needed to manage the process, such as its current state, ID, register values, and more.

It is essential for context switching, allowing the OS to stop one process and resume another without losing progress.

Component	Description
1. Process ID (PID)	Unique identifier for the process.
2. Process State	Current state of the process (e.g., New, Ready, Running, Waiting, Terminated).
3. Program Counter	Address of the next instruction to be executed for this process.
4. CPU Registers	Contents of all process-specific registers (like accumulator, stack pointer).
5. Memory Management Info	Includes page tables, segment tables, limits, and base registers.
6. Accounting Information	CPU usage, time limits, job or user IDs, etc.
7. I/O Status Info	List of I/O devices assigned, open files, and I/O requests.
8. Scheduling Info	Priority, pointers to scheduling queues, etc.
9. Parent/Child Info	Relationships between parent and child processes (if needed).