The Internet is a marvel of modern technology that connects people and information around the world. But have you ever wondered how it actually works?
In this blog post, we’ll break it down into easy-to-understand terms, so that anyone and everyone can understand how this invention works – and how it has changed the world.
How did the Internet begin?
Nikola Tesla introduced the idea of a “world wireless system” in the 1900s. From there, other visionaries such as Paul Otlet and Vannevar Bush began planning a searchable media database based on the idea from the 1930s and 1940s, a step that would lead to the modern Internet.
MIT scientist JCR Licklider came up with a solution in 1962: an “intergalactic computer network” that would allow communication on a global scale.
Licklider described what would eventually become the modern Internet. However, to do this, scientists will first need to come up with a new technology: packet switching.
Now, let’s take a deeper look at how data is transmitted over the Internet.
Circuit Switching and Packet Switching
There are two main methods of how we transport data: circuit switching and packet switching. Circuit switching is the equivalent of taking a train. Data is sent over a continuous connection, much like passengers traveling together in a train.
On the other hand, packet switching is similar to cars on the highway. Data is divided into smaller pieces called packets, which can take different paths to reach their destination. This flexibility allows more efficient and reliable data transmission.
But circuit and packet switching are not the only ways to share data, because just like in real life, these modes of transportation may not intersect each other, and experience a lot of traffic (data packets) on the same highway (channel). can do. Work properly – and may eventually stop.
By the early 1970s, ARPA’s packet-switching computer network (the imaginatively named “ARPAnet”) was growing and connecting with other packet-switching computer networks around the world.
But there was a problem: The computers operating on all these different computer networks couldn’t communicate with each other directly. There was no internet throughout the world. Instead, there was a bunch of mini-Internets.
To solve this problem, computer scientists developed the Transmission Control Protocol (TCP) and the Internet Protocol (IP).
Introduction to TCP/IP
TCP is responsible for dividing data into packets at one end of the transmission and reassembling those packets at the other end.
In comparison, IP is responsible for the formatting and addressing of the data packets being sent. That’s why every host computer on the Internet needs an IP address: a unique, numerical label that distinguishes one host from another. Without an IP address, data packets will not reach their proper destination.
When implemented together, TCP/IP is the communications language of the Internet, and was key to making the Internet a truly worldwide network.
Modern TCP/IP networks use four different layers to transmit data, and data always travels from one layer to the next.
- application layer: Responsible for interfacing with computer applications such as web browsers and email clients.
- Transport Layer: Where the Transmission Control Protocol (TCP) does the work of dividing the data into packets (and, on the receiving end, it reassembles that data).
- Internet Layer: Where Internet Protocol (IP) provides address information and determines which route the data will take.
- network layer: Physical hardware actually carries data through wires, fiber, radio, etc.
And to make sure we’re all on the same page here, let me give this quick analogy: sending data over a TCP/IP network is like sending a letter through the mail via the postal service.
- In the application layer, you are writing the actual letter you are going to send.
- In the transport layer, you are packing that letter in an envelope.
- In the Internet layer, you are writing the recipient’s address on the envelope, as well as your return address.
- And finally, in the network layer, you are putting the letter in the mail so that postal workers can deliver it.
The success of TCP/IP in the 70s meant that scientists in the 80s could actually have a lot of fun sending data to each other over the global network. However, there was still a big missing piece to the modern Internet we know and love today: the World Wide Web.
How was the World Wide Web created?
Until the 90s, there were no websites to collect them, and no World Wide Web. This all changed with software engineer Tim Berners-Lee, who first proposed the concept of the World Wide Web in 1989. By the end of 1990, he had successfully launched the first web page.
Berners-Lee was on a mission to create a more useful Internet – an Internet that was not just a network for sending and receiving data, but a “web” of data that anyone on the Internet could retrieve. To accomplish this, they needed to develop three essential pieces of technology, which are:
- Hypertext Markup Language (HTML): This is the standard protocol for publishing content on the web. It is used to format text and multimedia documents, as well as to link between documents.
- Uniform Resource Identifier (URI): Just as each computer on the Internet gets a unique identifier in the form of an IP address, each resource on the World Wide Web gets a unique identifier in the form of a URI. The most common type of URI is the Uniform Resource Locator or URL (also known as a “web address”).
- Hypertext Transfer Protocol (HTTP): HTTP is responsible for requesting and transmitting web pages. When you enter a URL in a web browser, you are actually initiating an HTTP command to find and retrieve the web page specified by that URL. With respect to TCP/IP networks, HTTP is part of the application layer, because specific applications – namely, web browsers and web servers – use HTTP to communicate with each other.
As Berners-Lee observed, the World Wide Web is the only thing we are using, connecting with, and learning from today. And it makes sense for us to see and find the information we’re looking for – just think of the Internet as a library of robots.
Simple explanation of how the Internet works
The Internet, or World Wide Web, operates as a giant library with friendly robots. Each book in this library represents a web page, and they all follow a specific format, which is HTML. When you know the call number, or URI, an assistant robot, which represents the HTTP protocol, retrieves the book for you. And if you don’t know the specific call number, search engines like Google can help you find the information you’re looking for.
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So this is how the internet works. Just remember this is just scratching the surface. If you’re curious to delve deeper into the intricacies of the Internet, our friendly robot, Google, is always there to help you with more information.
By understanding the fundamentals of the Internet and its technologies, you can gain a greater appreciation of the power and potential contained within this incredible tool.
Editor’s note: This post was originally published in October 2014 and has since been updated for comprehensiveness.
