What is Programming?

Programming is a way to talk to computers. Similar to how we use Hindi, English, or Bengali to communicate with people, we use programming languages to communicate with computers by giving them clear, step-by-step instructions.

Here's what programming involves:

By learning programming, you gain the power to create software that can run on computers, websites, mobile devices, and much more.

What is JavaScript?

JavaScript is a high-level, interpreted programming language originally designed to make web pages interactive. Today, it is one of the most popular and widely used languages in the world.

JavaScript can:

• Add interactivity to web pages (animations, forms, user input)
• Communicate with servers to fetch or send data (APIs)
• Build server-side applications using platforms like Node.js
• Create mobile and desktop apps through frameworks like React Native and Electron

It was invented by Brendan Eich in 1995, and has evolved through various standard specifications called ECMAScript (the official name of the language standard). Modern JavaScript supports advanced features like modules, classes, and asynchronous programming.

JavaScript is now a core skill for web developers, and has grown beyond browsers to power the modern software ecosystem.

JavaScript by Analogy

To understand JavaScript, think of a car:

What is ECMAScript?

You might often hear people mention ECMAScript when talking about JavaScript. ECMAScript is simply the standard specification that defines how the JavaScript language should work.

Think of ECMAScript as the “blueprint” for JavaScript — it describes the rules, features, and behavior that every JavaScript engine (like Chrome's V8 or Firefox's SpiderMonkey) must follow.

Key points about ECMAScript:

• Created by ECMA International: a standards organization
• First version released in 1997
• New features are published regularly (for example, ES6 introduced let, const, arrow functions, etc.)
• Ensures that JavaScript works the same way across different browsers and environments

In short, JavaScript is the language you write, and ECMAScript is the specification that keeps it consistent.

ECMAScript Versions

JavaScript evolves through versions of the ECMAScript standard. Each version introduces new features and improvements to make the language more powerful, cleaner, and easier to use.

Here's a quick overview of the most important versions:

• ES3 (1999): Widely adopted; introduced regular expressions and try/catch error handling.
• ES5 (2009): Added strict mode, JSON support, and better array methods (map, forEach).
• ES6 (2015): A major update — introduced let, const, arrow functions, classes, template literals, modules, promises, and much more.
• Later versions (ES7-ES15): Added async/await, optional chaining, top-level await, and many other modern features.

How JavaScript Works

JavaScript is designed to run inside web browsers, where it makes web pages interactive and dynamic. Every browser has a built-in JavaScript engine that reads and executes JavaScript code. For example, Chrome uses the V8 engine, while Firefox uses SpiderMonkey.

Here's what happens behind the scenes:

JavaScript uses an event-driven, single-threaded model. It processes one instruction at a time but uses an event loop to handle things like clicks or data fetching without blocking the entire program.

Where JavaScript is Used

JavaScript has grown far beyond simple web page scripts. Today, it is used in a wide variety of applications and platforms: