Summary  
This chapter explains the HTTP request–response model between a client and server and the step-by-step process by which a browser retrieves and combines resources (HTML, CSS, JavaScript) to render a webpage.

General domain of usage  
Web development


When you open a website, your browser communicates with a server.

A **browser** is the application you use to access websites. A **server** is a machine that stores data and sends it when requested.

This communication is based on a simple concept: **request and response**.



### How It Works

1. Your browser sends a request when you enter a URL;
2. The server processes the request and prepares the data;
3. The server sends a response back;
4. Your browser displays the result as a webpage.



### How a Page Is Loaded

When you open a website, the browser does more than just load a single file.

* The browser requests the main HTML file;
* The server returns the HTML;
* The browser requests additional files like CSS and JavaScript;
* The server sends those files;
* The browser combines everything and renders the page.

This all happens in milliseconds, giving you a complete website on the screen.


Understand how the web works and how backend systems operate behind the scenes. Learn how browsers and servers communicate, what backend developers actually do, and how tools like Node.js and Nest.js fit into modern development.

What Is the Web and How It Works

How It Works

How a Page Is Loaded