How The Internet works ?
How the Internet works ?

How the Internet works ?

Priyansu Dash's photo
Priyansu Dash
·

5 min read

Topics:-

  1. The Internet: How it works and Why it Matters

  2. From Browsers to Servers: The Journey of our data

  3. Breaking down the WWW: A Beginner’s guide

  4. Understanding the backbone of the Internet: IP addresses, Domain Names, and Routing

My Selected Topic: From Browsers to Servers: The Journey of Our Data

Here are the three main components: the client, which is often a browser (though not always), the web server, and DNS.

Summary of this Diagram
The diagram explains the process of client-server communication over the internet. It begins with the client, such as a web browser, sending an HTTP/HTTPS request to access a specific resource. The request is first routed to the DNS server, where the domain name is resolved into an IP address by searching the DNS database. Once the IP address is obtained, the request is routed through the internet backbone to the web server hosting the resource. The web server processes the request, generates the required response, and sends it back to the client through the same internet backbone. This process ensures seamless data exchange between the client and server.

Let's simplify the jargons using analogy, which is a real-life example that can be the smartest way to understand.

  1. Client:-

A client can be a browser, a mobile application, or something else, but in most cases, the client is a browser.

Browser :-

→ The web browser is an application software to explore www.

→ It provides an interface between the server and the client and it requests to the server for web documents and services.

→ Examples of Browser are Chrome, Safari, Firefox and etc.

Example:

Summary of the Diagram with a Example
When you type google.com into your browser, the browser sends a request to a DNS server to resolve the domain name into an IP address. Once the IP address is obtained, the browser uses it to send an HTTP/HTTPS request to the web server. If it's an HTTPS request, a secure connection is established through a TLS/SSL handshake. The web server then responds with the requested resources, which the browser processes to display the web page.

Analogy:- When you go to a big-store to buying some things, the store keeper take your list which are noted in a paper and search in his database what is present or not then He goes to the store and get your items.

In this case You are the User, The store keeper is the Browser, His database is DNS Database, and his store is the server

  1. DNS:-

→ Known as Domain Name System.

→ It is like contacts of your mobile

Summary of the Diagram
When you type google.com in your browser, the request is sent to a DNS resolver, which queries a DNS server to find the IP address associated with the domain. The server searches its database (zone file) for the relevant DNS records, such as A or AAAA records, which map domain names to IP addresses. The DNS server may cache the results to improve lookup speed for future requests. The process involves the server and its database working together to resolve the domain name into an IP address.

Without DNS, users would have to remember complex IP addresses instead of simple, user-friendly domain names

Analogy: When you need to call someone but don't remember their phone number, you can search for their name in your phone contacts. This helps you find their number to make the call. In this analogy, the DNS is like the contact list, and the phone memory is the database where the contacts are stored.

  1. Server:-

    →A server provides services to clients, such as ordinary desktop computers or workstations. It is a centralized machine where multiple clients connect over the internet or a local network to access specific services.

    → When people refer to a server, they mean a powerful centralized computer that clients connect to over a network. However, a server is not just a physical computer; it is a role that a computer takes on. Any ordinary desktop computer can be set up as a server.

    → Servers are set up to run 24/7 because if a server goes down, it could jeopardize an organization's business.

    → There are 13 root servers in the worldwide. You can check it using the link.

Summary of the Diagram
This diagram illustrates a client-server model, where multiple clients (Client-1, Client-2, Client-3, and Client-4) communicate with a central server. After obtaining the IP address of a specific domain, the browser sends it to a nearby server in an HTTP/HTTPS request. The server processes the request and sends the response back to the browser in HTTP/HTTPS format.

Let’s elaborate the summary:-

step-1:- The browser first resolves the specific IP address of a particular domain using a DNS query

step-2:- After obtaining the IP address, the browser connects to the server at that address. If the communication is over HTTPS, the browser and server first perform a TLS handshake to create a secure, encrypted connection. The browser then sends an HTTP or HTTPS request, like a GET or POST request, to the server.

step-3:- The server receives the request, processes it (e.g., retrieves data, executes scripts, or accesses a database), and prepares the appropriate response.

step-4:- The server sends the response back to the browser in HTTP/HTTPS format, often including content like HTML, CSS, JavaScript, images, or JSON data.

step-5:- The browser receives the response and renders the content for the user to view.

Analogy:- When you go to a shop to buy something, you're not the only customer there. There are many others. All the customers are like clients, and the shopkeeper is like the server. However, unlike a server, the shopkeeper can't work 24/7.

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