In today's world, computers play a vital role in our lives. Sometimes, you might have heard about computer networking, which is like connecting two computers together. Imagine there are two computers, one called Computer A and the other Computer B. They can talk to each other using computer networking.
The Beginning of Computer Networking: A Brief History
A long time ago, Russia, also known as the Soviet Union. They sent a special thing called a satellite named Sputnik into space. That was a huge deal back then! This made the United States feel excited and a bit challenged. They wanted to be really good at lots of things, like being the first on the moon and inventing amazing stuff. To make this happen, the USA created a club called ARPA. Later on, they changed the name to DARPA. Inside DARPA, there were special universities like UCLA, SRI, UCSB, and the University of Utah. These smart people wanted to talk to each other, but guess what? It was super tricky back then.
So, they did something incredible: they invented the internet. This allowed these universities to communicate, and that's how the era of the Internet began. They used something called TCP protocol, which made sure data travelled safely and in order.
Connecting the World: The Birth of the World Wide Web
As time went on, a new problem came up. Imagine you wrote a document and wanted to include a link to another document inside it. This was tough in the early days of the Internet. But a person named Tim Berners-Lee had a solution. He launched something called the World Wide Web (www). It had rules: you could create web pages with links, but you couldn't search for things easily. There were no search engines at that time. Later on, Yahoo launched and helped with searching.
Setting the Rules: The Internet Society
You might wonder who decides the rules for the internet. Well, there's an organization called the Internet Society that does just that. It was formed in the USA and helps make sure the internet works smoothly.
Understanding Client-Server Architecture
Now, let's talk about how computers communicate. Think of it like this: the computer you're using is a client, and it sends requests to a server. The server then sends back responses. It sounds simple, but a lot happens behind the scenes.
Protocols: How Computers Talk
There are special rules that computers follow when they talk. Some of these rules are:
TCP: This rule makes sure data is sent correctly and in the right order.
UDP: This one is faster than TCP, but it doesn't promise that data will always be perfect. We use it for things like video calls and games.
HTTP: Web browsers use this rule to load web pages.
Sending Data in Packets
When computers send information to each other, they split it into small packets. These packets have the sender's address and the receiver's address.
IP Address: The Computer's Home Address
Every computer has a special address called an IP address. It's like a home address for your computer on the internet. To make it easier for humans, we assign names to IP addresses. For instance, the IP address 192.168.3.1 is like the address for Google.com.
Imagine this like a phone diary. We have numbers for different people, but we remember names better. In the same way, computers use names to find each other on the internet.
How Does the Internet Actually Work?
First and foremost, you all have an understanding of how the client-server architecture works. Now, let's delve deeper into this concept. Imagine there is an internet connection, and you have your computer or mobile device. Between the internet and you, there exists an entity known as the ISP (Internet Service Provider). Let's assume you are using Airtel as your ISP.
Beyond the ISP, there is a modem. The modem possesses a global IP address. Its primary function is to gather requests from various devices. Furthermore, the modem is responsible for transmitting the responses received from servers using DHCP. Here arises a question: when numerous devices send requests to the server, all utilizing the same ISP and modem, how does the modem distinguish which IP address initiated each request? The answer lies in NAT (Network Address Translator). NAT is employed to discern the device responsible for sending the request.
Now, let's address another query. How does the modem ascertain which application triggered the request? So far, we have grasped the use of NAT to identify the sending device. However, there remains the issue of identifying the specific application—was it Google, Facebook, or another entity? This identification is established through the use of ports. Each application is assigned a distinct port number. For instance, the widely used port 80 is allocated to HTTP.
In a nutshell, computer networking is how computers talk to each other, share information, and make the internet work. It has come a long way from the early days of connecting universities to the worldwide web we use today. It's fascinating how a few universities trying to communicate led to a revolution that changed the world!