---
title: "Process vs Thread: Key Differences"
description: "Understand the core differences between processes and threads."
image: "https://assets.bytebytego.com/diagrams/0304-program-process-thread.png"
createdAt: "2024-03-12"
draft: false
categories:
  - computer-fundamentals
tags:
  - "Operating Systems"
  - "Concurrency"
---

![](https://assets.bytebytego.com/diagrams/0304-program-process-thread.png)

To better understand this question, let’s first take a look at what a Program is. A Program is an executable file containing a set of instructions and passively stored on disk. One program can have multiple processes. For example, the Chrome browser creates a different process for every single tab.

A Process means a program is in execution. When a program is loaded into the memory and becomes active, the program becomes a process. The process requires some essential resources such as registers, program counter, and stack.

A Thread is the smallest unit of execution within a process.

The following process explains the relationship between program, process, and thread.

1.  The program contains a set of instructions.

2.  The program is loaded into memory. It becomes one or more running processes.

3.  When a process starts, it is assigned memory and resources. A process can have one or more threads. For example, in the Microsoft Word app, a thread might be responsible for spelling checking and the other thread for inserting text into the doc.

## Main differences between process and thread:

*   Processes are usually independent, while threads exist as subsets of a process.

*   Each process has its own memory space. Threads that belong to the same process share the same memory.

*   A process is a heavyweight operation. It takes more time to create and terminate.

*   Context switching is more expensive between processes.

*   Inter-thread communication is faster for threads.