2.1. The Internet and the Web

Table of Contents

Understanding "The Internet" vs "The Web"

When people say they are "on the internet", they often mean they are "using the web". For backend development, it is important to know the difference between these two, and how they work together to let users talk to your backend applications.

In this chapter, you will learn what the internet actually is, what the web is, how they are related, and what parts matter for backend developers.

The Internet as a Global Network

The internet is a huge global network of connected computers and devices. It is the physical and logical infrastructure that allows machines to send data to each other.

You can imagine the internet as a giant system of roads and highways. Every computer, phone, router, and server is like a building next to some road. When you send data, you are sending a "truck" that travels along these roads from one building to another.

The internet includes many things besides websites in your browser. For example:

Email uses the internet but not the web.
Online games use the internet but not necessarily the web.
File sharing, video calls, and messaging apps all use the internet, sometimes with their own protocols.

All these different uses are built on top of the same underlying communication network, but they can use different rules and formats to talk.

The Web as an Application on the Internet

The World Wide Web, usually just called "the web", is a way of using the internet to access linked documents and resources.

Web browsers such as Chrome, Firefox, and Safari talk to web servers using the HTTP or HTTPS protocol to request and display web pages, images, scripts, and APIs.

You can think of the web as one specific "application" that runs on top of the internet. It uses the internet roads, but it has its own rules for how to format and request content.

This means:

The internet is the network.
The web is a set of services and content that use that network, mostly accessed by browsers and HTTP clients.

Other applications that use the internet but are not "the web" include:

Email, which usually uses SMTP, IMAP, or POP3 protocols.
SSH, which lets you connect to remote servers through a terminal.
FTP or SFTP, which transfer files.

As a backend developer, you mostly work with the web, but you must understand that behind the web there is a more general internet infrastructure.

Key Components of the Internet

The internet is made of many connected networks. To keep millions of devices connected, a lot of elements work together.

Here are some important components:

User devices such as laptops, phones, and tablets.
Routers that direct traffic between networks.
Internet Service Providers (ISPs) that connect users and companies to the broader network.
Data centers where servers are hosted.
Undersea cables and satellites that connect countries and continents.

When you access a backend API that you wrote, your request travels from your device, through local networks and your ISP, across the wider internet, to the data center where your server runs.

You do not need to know all the physical details to be a backend developer, but it helps to know that the internet is a network of networks, with many small and large pieces working together.

How the Web Uses the Internet

The web uses the internet to deliver web pages and APIs.

When you open a website, your browser does roughly the following:

Finds the server address for the website you entered.
Connects to that server over the internet.
Sends HTTP requests to ask for specific resources, such as an * HTML page or a JSON API response.
Receives HTTP responses and displays them or uses them.

The "finding the server" part uses domain names and DNS, which you will see in later chapters. The "sending and receiving" part uses TCP/IP and HTTP or HTTPS, which you will also study in detail.

So the web is:

A collection of documents and services, mainly HTML, CSS, * JavaScript, images, videos, and APIs.
Interlinked using URLs and hyperlinks.
Accessed mostly with web browsers and HTTP clients.

Your backend services are usually web servers, and they speak HTTP over the internet.

Internet Protocols vs Web Protocols

Communication on the internet is defined by protocols, which are agreed rules about how to format and send data.

You can think of protocols as languages with strict grammar. If both sides speak the same protocol correctly, they can understand each other.

There are general internet protocols and more specific web protocols.

General internet protocols include:

IP, which is used to address and route data between devices.
TCP and UDP, which define how data is broken into packets and delivered.

On top of these general protocols, there are application protocols.

Web protocols include:

HTTP and HTTPS, which define how browsers and web servers talk.
WebSocket, which can create long lived connections for real time communication.

Other non web application protocols include:

SMTP for email sending.
SSH for remote shell access.

In later chapters you will focus mostly on HTTP and HTTPS, because that is what browsers and web APIs use. But remember that they live on top of lower level internet protocols.

The Birth of the Internet and the Web

The internet and the web were created at different times for different purposes.

The early internet began as a research network to connect computers across universities and government institutions so that they could share data and survive partial failures.

The web was invented later as a way to organize and share documents using hyperlinks. It gave us concepts such as web pages, URLs, and browsers.

Although today many people mix the words "internet" and "web", they are not the same thing. The internet is the foundation, the web is a popular application on top of that foundation.

Why Backend Developers Must Understand the Difference

As a backend developer, you will build web backends that live on the internet, so you need to think about both layers.

You must understand the web protocols, such as HTTP, to design and implement APIs correctly.
You must also understand some basics of the internet, such as IP addresses, ports, and DNS, so that your services are reachable and work reliably.

For example:

When your API is not reachable from a browser, the issue might be in your web code, but it might also be in the internet side, such as DNS misconfiguration, firewall issues, or wrong ports.

When you choose to use HTTPS instead of HTTP, you are still using the same internet, but with encryption on top.

Understanding the separation helps you debug problems more effectively.

Common Misconceptions

Because people use the words "internet" and "web" casually, some ideas become confusing. Let us clarify a few.

Saying "the internet is down" can mean many different things. Maybe your local Wi Fi is broken, your ISP has a problem, DNS is not working, or a specific website is down. The global internet is extremely resilient, and usually only parts of it are unreachable.

Websites live on the web, but the servers that host them are part of the internet infrastructure. When a particular website is unavailable, the whole internet is still functioning.

APIs you build are usually web APIs, because they use HTTP. However, you could in theory build backend services that talk with other protocols on the internet, not just HTTP.

It is possible to use the internet without a browser. For instance, you can use command line tools, custom clients, or non web applications that communicate directly with your backend.

Example: Experiencing the Internet Without the Web

To make the difference more concrete, consider the following examples.

Using SSH to log into a remote Linux server is using the internet, but not the web. You are using the SSH protocol on top of TCP/IP to open a secure terminal session.

Sending an email with a desktop mail client involves the internet, but not the web browser. Email servers use SMTP, IMAP, and POP3 protocols across the same network.

Running a multiplayer game that syncs with a game server also uses the internet. The game client and game server might use custom binary protocols on top of UDP or TCP, not HTTP.

In all of these cases, the devices use the internet, but not the web.

Then consider an example with the web.

Opening a REST API URL such as https://api.example.com/users in your browser is using both the internet and the web. Your browser connects to the remote host over the internet and speaks HTTP to request that resource.

As a backend developer, when you create the /users endpoint, you are building a web service that depends on the lower internet layers.

Summary and Connection to Upcoming Topics

You can remember the relationship like this:

The internet is the network that connects computers worldwide.
The web is one way of using that network, mainly with HTTP and browsers.

Important:
"The internet" is the global network infrastructure.
"The web" is the system of web pages, APIs, and resources accessed primarily via HTTP or HTTPS, usually in a browser.

In the following chapters, you will dive deeper into how this system works in practice:

IP addresses, which identify devices on the internet.
Domain names and DNS, which map human friendly names to IP addresses.
TCP/IP basics, which explain how data is broken into packets and delivered.
HTTP and HTTPS, which define how web clients and servers exchange requests and responses.

All of those concepts sit between your backend code and the users who access it through the web. Understanding where the internet ends and the web begins will help you see how these pieces fit together.