A process is the operating system’s abstraction for a running program

  • Running: In the running state, a process is running on a processor. This means it is executing instructions.
  • Ready: In the ready state, a process is ready to run but for some reason the OS has chosen not to run it at this given moment.
  • Blocked: In the blocked state, a process has performed some kind of operation that makes it not ready to run until some other event takes place. A common example is when a process initiates an I/O request to a disk. It becomes blocked, allowing some other process to use the processor.

State Machine of a process

Zombie Process