When a process executes, it passes through different states. These stages may differ in different operating systems.
In general, a process can have one of the following five states at a time.
•1) Start- This is the initial state when a process is first started / created.
•2) Rady - The process is Waiting to be assigned to a processor. Ready processes are waiting to have the processor allocated to them by the operating system so that they can run.Process may come into this state after start state or while running it by but interrupted by the scheduler to assign CPU to some other process.
•3) Running - After Ready state, the process state is set to running and the processor executes its instruction.
•4) Waiting- Process moves into the waiting state if it needs to wait for a resources, such as waiting for user input, or waiting for a file to become available.
•5) Terminated or Exit- Once the process finishes its execution, or it is terminated by the operating system, it is moved to the terminated state where it is waits to be removed from main memory.