What is a process in operating system? What are the process states?

Last updated on August 29th, 2020 at 09:51 am


A process can be thought as a program in execution, but a program by itself is not a process. Process is nothing but a set of instruction to be executed. Multiple instances of a single process can be running at any given time and also a process may create sub-processes with time. Processes may need certain resources like, CPU time, memory, files and access to other devices.

What is a process in operating system? What are the process states?

As being said, process is a set of instruction, it can be considered that a batch job is a process. CPU execute instructions in a process in a sequential manner, one instruction after another until the process is complete.
A process is more than the program code. It includes the current activity which is the value of the program counter, and the contents of the processors registers, a process stack containing temporary data and a data section containing global variables.
The operating system is responsible for the following operations in connection to process management.
  1. Creation and deletion of both user and system processes
  2. Suspension and resumption of processes
  3. Provision of mechanism for process
    • Synchronization
    • Communication
    • Deadlock handling

Process States:

Each process in progress may be in one of the following states
  • New: The process is being created.
  • Running: Instructions from the process are being executed.
  • Waiting: The process is waiting for some event to occur, like an I/O activity etc.
  • Ready: The process is waiting to be assigned to a processor
  • Terminated: The process is completed.