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Jayashree
Jayashree

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What is JavaScript? – A Simple Guide for Beginners

Introduction

Today, almost every website and app uses one powerful programming language — JavaScript.
When you click a button and a popup appears, when a form shows an error, when a page loads new content without refreshing… all these happen because of JavaScript.

This blog is written in very simple English for complete beginners.

What is JavaScript?

JavaScript is a programming language mainly used to make websites interactive and dynamic.

HTML ➝ gives structure

CSS ➝ gives style and design

JavaScript ➝ gives life and action

Without JS, websites would look like plain text and images.

Where is JavaScript used?

JavaScript is not only for websites. It is used everywhere today:

  • Websites

Buttons

Sliders

Animations

Form validations

Pop-ups

  • Mobile Apps

Using frameworks like React Native and Ionic.

  • Backend / Servers

With Node.js, JavaScript can run on servers too (used by Netflix, Uber, etc.)

  • Desktop Apps

Apps like VS Code and Slack are made using JavaScript.

How does JavaScript work?

  • Runs in the browser or Node.js
  • Executes code line by line
  • Single-threaded (one thing at a time)
  • Async tasks (timers, API calls) are handled using the event loop.This makes JavaScript non-blocking

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