🌐 World of computer networking

Every day, we use the Internet for various activities—browsing websites, messaging friends, sending emails, or making video calls. And at some point, most of us have probably asked ourselves: How does all of this actually work? Behind every action we perform online lies a complex web of computer networking. But what exactly makes up this network, and how does it function?

We often hear terms like Domain Name, IP Address, Server, and ISP, but what do these really mean, and how are they all connected? That’s exactly what we’ll explore in this article.

So, let’s dive in.

But before we get into the modern world of computer networking, let’s take a step back and look at the origins of the internet—and how we evolved from the age of radio to the connected digital world we live in today.

🕰️ A Brief History of the Internet

Cold War period resulted in many great innovation and internet is one of them. During the height of Cold War America wanted a communication system which is faster, secure and could survive nuclear attacks so they created ARPANET in 1969 also known as The First Internet. This technology at first connected four main universities of USA which were UCLA, Stanford, UC Santa Barbara, University of Utah to share information between them easily through Leased telephone lines.

Earlier ARPANET used a protocol called NCP (Network Control Protocol) which was like a walkie-talkie between two computers — it could handle basic connections but didn’t support multiple networks talking to each other. Then came in TCP/IP protocol suite developed officially in 1970 by Vint Cerf and Bob Kahn.

TCP/IP protocol was adopted by ARPANET on January 1, 1983. That day is often called the "Birth date" of the internet. TCP/IP works on two parts one TCP if you want to send a data to someone TCP chops the data in smaller packet then each packet is numbered and sent out separately — they might take different routes. IP takes care of the addresses — like writing the "To" and "From" on each packet. When the packets arrive at the destination, TCP puts them back together in the right order.

By the mid to late 1980s, the Internet supported email, file transfers (FTP), and remote login (Telnet). However, it was far from the current internet which we are used to now. Back then, visiting a website was like opening a plain document —there were no images, no videos, and no user interaction. Websites were static pages filled with basic text-based information. That all began to change thanks to the vision of one man.

In 1989, Tim Berners-Lee proposed a system to share information over the Internet using hyperlinks. Working at CERN, he saw the need for a more organized and accessible method to navigate the growing body of digital information. His idea led to the creation of the World Wide Web—a system that allowed users to easily browse and connect documents using hypertext.

By 1991, the first website was up and running. To make this possible, Berners-Lee developed three core technologies:

• HTML (HyperText Markup Language) – used to create and structure web pages.
• HTTP (HyperText Transfer Protocol) – the protocol for transferring web pages.
• URL (Uniform Resource Locator) – a unique address to find any resource on the web.

This marked the beginning of modern Internet and gave way to Languages like HTML, CSS & Javascript to be the standart way of building websites.

🖥️ Client-Server Architecture

Every time we visit a website, we receive information, but behind the scenes, a lot of communication takes place between computers, potentially located in different parts of the world.

To understand this communication, we first need to know what a client and a server are.

A client is the device or software that initiates the conversation by sending a request. For example, when you visit a website like youtube.com, your browser (the client) sends a request to the server to retrieve information and data from that website.

A server is the computer that responds to the client's request by sending the requested data or information. In this case, the computer hosting youtube.com is the server that handles all the data and resources for the site.

📍 What Is an IP Address?

Every device which is connected to the internet has a unique IP address. An IP address (Internet Protocol address) is a unique string of numbers like this 192.168.1.15 which identifies client and server and help them establish connection to send or receive data.

Just like your house has a unique address so mail can find you, every device—be it your phone, laptop, tablet, or even smart TV—needs an IP address so that data from the internet knows exactly where to go.

🔍 How IP Addresses Work

When you open an app or browser on your device and request something from the internet—like loading a website or sending a message—your request is sent out with your IP address attached. That request travels through your local network, reaches your Internet Service Provider (ISP), and is then routed to the correct server. The server uses your IP address to send the information back to your device.

📊 Breaking Down an IP Address

Let’s take an example IP address: 192.168.1.15

This is an IPv4 address (there's also IPv6, which is longer and used as the internet grows).

• 192.168.1.15 is made up of four numbers separated by dots.
• Each number is called an octet and can range from 0 to 255.
• Together, they represent the network and host portions of the address.

Here’s what each part might mean:

• 192.168 — This identifies the network your device is connected to. This range (192.168.x.x) is reserved for private networks (like your home Wi-Fi).
• 1 — This can define a sub-network (called a subnet) within your main network.
• 15 — This identifies the specific device on that subnet (e.g., your laptop).

🧭 How IPs Are Assigned

When you connect a device to the internet, it gets an IP address in one of two ways:

1. Automatically via DHCP: Most devices get their IP address automatically using a service called DHCP (Dynamic Host Configuration Protocol).
• At home, your Wi-Fi router assigns private IP addresses (like 192.168.1.15) to devices within your local network.
• Your ISP (Internet Service Provider) assigns a public IP address to your router—this is what the outside internet sees.
2. Manually (Static IP): In some advanced setups, a user can assign a fixed IP to a device—useful for servers or IoT devices.

🔌 Ports: Apartment Numbers for

Every device can run multiple applications, and each of those apps needs a way to send and receive data. That’s where ports come in.

Let’s break this down:

• Imagine your device as an apartment building (your IP address is the building’s address).
• Each app or service is like an apartment inside the building, and each one has a port number.
• When a website sends data back to your device, it’s not just sent to your IP address—it’s sent to a specific port, which tells your device which app requested it.

For example:

• Web browser might use port 80 or 443 (HTTP/HTTPS)
• Email app might use port 25 or 587 (SMTP)
• Game or video call app might use dynamic ports for real-time data

When you click on a link in a browser:

1. The browser sends a request through your device's IP and a specific port.
2. That request travels through your router, gets your ISP's public IP, reaches the destination server.
3. The server processes the request and sends the response back to your public IP and port.
4. Your router forwards it to the correct device and app based on internal IP and port mapping.

📘 Protocols: The Language of the Internet

 In the world of computer networking, protocols are like languages or rulebooks that computers follow to communicate with each other. Without them, devices wouldn’t understand how to send or receive data. Each protocol is designed for a specific type of communication—whether it's browsing websites, sending emails, or transferring files. Here are some of the most important and commonly used networking protocols:

1. HTTP/HTTPS (HyperText Transfer Protocol / Secure)

• Used for: Browsing websites.
• How it works: HTTP is the protocol your browser uses to communicate with web servers and load websites. HTTPS is the secure version of HTTP—it encrypts the data using SSL/TLS so that no one can spy on what you're doing.
• Example: When you visit https://example.com, your browser uses HTTPS to securely fetch the website’s data.

2. TCP (Transmission Control Protocol)

• Used for: Reliable communication between devices.
• How it works: Breaks data into packets, numbers them, sends them to the destination, and ensures they arrive correctly and in order. If a packet is lost, TCP resends it.
• Example: Used in browsing, emails, file transfers—anything where accuracy matters.

3. IP (Internet Protocol)

• Used for: Routing data across the internet.
• How it works: Assigns addresses to devices and handles the actual delivery of data packets from one IP address to another.
• Example: Every email or website request relies on IP to reach its destination.

4. UDP (User Datagram Protocol)

• Used for: Fast, real-time applications.
• How it works: Sends data without checking if it was received correctly—trades reliability for speed.
• Example: Online gaming, video calls, or live streaming—where real-time speed matters more than perfect accuracy.

5. DNS (Domain Name System)

• Used for: Translating domain names into IP addresses.
• How it works: When you type google.com, DNS helps your browser find the actual IP address of Google’s servers.
• Example: Without DNS, we’d have to memorize long IP addresses instead of simple domain names.

6. FTP (File Transfer Protocol)

• Used for: Transferring files over a network.
• How it works: Allows you to upload or download files between your computer and a remote server.
• Example: Web developers use FTP to upload website files to their web servers.

7. SMTP, POP3, IMAP (Email Protocols)

• Used for: Sending and receiving emails.
• SMTP (Simple Mail Transfer Protocol): Used to send emails.
• POP3/IMAP: Used to receive and manage emails.
• Example: When you send an email from Gmail, it uses SMTP; when you check your inbox, Gmail may use IMAP.

Each of these protocols plays a specific role in the digital world. Together, they create a structured and organized system that allows billions of devices to communicate seamlessly every second of the day.

✅ Final Thoughts

Computer networking is the silent backbone of the digital age. From the moment you load a website to sending a message across the world—it all depends on well-structured systems, protocols, and addresses working in harmony.

Understanding the basics not only helps you appreciate modern technology, but also empowers you to troubleshoot, build, or even innovate in this fascinating domain.