Question Answer

Basic Difference Between Process and Thread

A process is an independent program with its own memory and resources, while a thread is a lightweight unit of execution that runs inside a process and shares the process’s memory.

Key Differences (Process vs Thread)

• Definition:
  • Process: A running instance of a program.
  • Thread: A sub-task (execution path) inside a process.
• Memory & Resources:
  • Process: Has its own separate address space and resources.
  • Thread: Shares the process’s memory (heap) and resources; has its own stack.
• Isolation & Safety:
  • Process: Strong isolation; one process crash usually doesn’t affect others.
  • Thread: Weaker isolation; a faulty thread can affect other threads in the same process.
• Communication:
  • Process: Uses Inter-Process Communication (IPC) like pipes, sockets.
  • Thread: Communicates via shared memory (faster but needs synchronization).
• Overhead & Speed:
  • Process: Heavier to create and context switch.
  • Thread: Lighter, faster to create and switch.
• In Java (CSE context):
  • The JVM runs as a process.
  • Java threads (e.g., main thread, worker threads) run inside the JVM process and share the same heap.

One-Line Summary

Process = independent program with separate memory; Thread = lightweight execution unit inside a process that shares memory.