A process goes through different states from creation to termination.

1. New

• The process is being created.
• The OS allocates memory and resources.

Example: You double-click Chrome.

2. Ready

• The process is ready to run.
• It is waiting for the CPU.

Example: Chrome is loaded into memory but waiting for the CPU to execute it.

3. Running

• The CPU is executing the process.

Example: Chrome is opening a webpage.

4. Waiting (Blocked)

• The process is waiting for an event or I/O operation to complete.
• During this time, it does not use the CPU.

Example:

• Waiting for a file to be read.
• Waiting for data from the internet.
• Waiting for user input.

5. Terminated (Exit)

• The process has finished execution or has been stopped.
• The OS releases its memory and resources.

Example: You close Chrome.

Process Lifecycle

New
  │
  ▼
Ready
  │
  ▼
Running
 ├─────────────► Terminated
 │
 ▼
Waiting
 │
 ▼
Ready

State Transitions

• New → Ready : Process is created.
• Ready → Running : CPU scheduler assigns the CPU.
• Running → Waiting : Process requests I/O or waits for an event.
• Waiting → Ready : I/O or event completes.
• Running → Ready : CPU time slice expires (context switch).
• Running → Terminated : Process finishes execution.

Interview Tip

A process spends most of its lifetime alternating between Ready, Running, and Waiting until it eventually reaches Terminated.