It’s often the simple questions that baffle us the most. For a society entrenched in technology, it seems silly to even entertain the question of what the Internet is made of. Why, of course, it’s… it’s made of my favorite websites? Although we are painfully aware of the times when we cannot connect to “the Internet”, what are we connecting to, exactly? Where is this Internet located, and what is it made of?
The short answer is that the Internet is really a network of billions of computers around the planet that are connected together. When you connect to the Internet, you’re simply joining this network of computers.
Every computer in this network is assigned a unique address so they can talk to each other. This address is called an IP address (IP stands for internet protocol). For example, Google.com’s IP address is “184.108.40.206”. You can type those numbers and dots in your browser and you will land on Google’s website (try it!).
Memorizing telephone numbers is difficult enough that we shouldn’t have to memorize the IP addresses of websites. To solve this problem, there are computers on the Internet called DNS Servers (DNS stands for Domain Name System) whose job it is to translate website URLs to IP addresses: When you type ‘google.com’ in your browser, your computer connects to DNS servers, which then redirect you to the computer identified by the IP address ‘220.127.116.11’.
Think of it as getting in a taxi and requesting to go to the train station when you don’t know the exact address; before driving you there, the taxi driver’s must translate your vague request into an address.
But what’s the formula for translating ‘google.com’ to ‘18.104.22.168’? In reality, there are none, it’s much simpler than that. The numbers are completely unrelated to the website itself; in fact, the DNS servers simply maintain tables that map domain names to IP addresses. If you enter an invalid website domain, the DNS server will not have the listing for that website and will contact other DNS servers to see if they can map the domain name you provided. After a while (this would only take milliseconds), the DNS server gives up and returns an error message.
I mentioned earlier that all computers on the web are assigned an IP address. By that definition, it means that your computer is also assigned such an address when you connect to the Internet. To find out yours, go to Google.com and search for “my IP address”.
A common misunderstanding is that your IP address should not be shared with others; otherwise, the hackers will get you. The truth is that your IP address is public information, much like the house number on your mailbox. Displaying your house address does not make the lock on your front door any less secure. Similarly, your computer is set by default to not accept such connections from the outside—your doors are locked.
You may have noticed that I’ve used the terms ‘internet’ and ‘web’ interchangeably. The sad truth is that those two terms mean very different things. The term ‘Internet’ refers to the network itself, whereas the ‘web’ is an application that runs over the Internet. The languages and conventions used to communicate over the Internet are called protocols. For example, the web uses the HTTP protocol while you need the SMTP protocol to send e-mails.
The first use of the word ‘Internet’ was in 1974. In the early days, when the creators of the Internet thought about how to best implement this network, they opted for a design that favored flexibility. In his monumental 1988 paper “The Design Philosophy of the DARPA Internet Protocols“, David D. Clark explains the decision to opt for the ‘end-to-end principle’ , which argues that the network be kept as simple as possible by implementing functionality at the ends of the networks rather than making such functionality a defining part of the network, thereby imposing restrictions on the future growth of the Internet.
It was only in 1990 that Tim Berners-Lee and Robert Cailliau invented the World Wide Web (yes, it’s only been that long). Initially, it was meant as a medium for physicists to share papers and data, and allowed browsing the information using ‘hypertext links’.