What Is the Internet, Really?

Published on TechForEverybody · Estimated read time: 15 minutes

You've Used It a Thousand Times — But What Is It?

Picture this: you're on a video call with a friend, right in the middle of a story, and suddenly their face freezes mid-laugh. The spinning wheel appears. "Sorry, bad internet," one of you mutters and everyone nods like that explains everything. But does it? What actually just happened? Where did your words go? What is this invisible thing called "the internet" that we rely on for almost everything, yet almost nobody can explain?

By the end of this post, you will be able to answer that question clearly, confidently, and without needing a computer science degree. We will follow one single journey from the moment a person types a website address all the way to the moment that website appears on their screen. Every step will be explained in plain language first and then in the real technical terms that engineers use. Let's go.

Let's Start Simple: The World's Biggest Postal Network

Forget everything technical for a moment. Let's talk about letters.

Imagine the internet as the world's most enormous and fastest postal network, one that spans every country, every city, and every home on earth. Instead of sending paper letters, you are sending information: a message to a friend, a request to see a webpage, or a video streaming to your screen. But the basic idea is exactly the same as old-fashioned post. You want to send something from your place to someone else's place, and you need the postal system to figure out how to get it there.

In the real postal world, every house has a unique address. That is how the post office knows where to deliver your letter. The internet works the same way. Every device connected to it, whether it is your phone, your laptop, or your smart TV, has its own unique address. Think of it as your house number on the internet's global street map.

Now imagine your friend Sarah sitting at her laptop, and she wants to watch something on Netflix. She types netflix.com into her browser and presses Enter. What she has just done, in postal terms, is write a letter saying "Please send me the Netflix homepage." But there is a small problem before that letter can go anywhere. The postal network does not work with names like "Netflix." It only works with numbered addresses. So before anything else can happen, someone needs to look up Netflix's address for Sarah.

That is where the internet's version of a phone book comes in. There is a service that keeps a giant directory of names and their matching addresses. You hand it a name like netflix.com and it flips through the directory and hands you back the exact street number. Only once Sarah's letter has the right address on it can it actually be delivered.

Once the address is known, Sarah's request does not travel as one whole letter. Imagine the postal service said: "We cannot carry a letter this big all at once. We will cut it into small numbered pieces, send each piece separately via the fastest available route, and put them back together perfectly at the other end." That is exactly what the internet does. Sarah's request gets chopped into tiny chunks, each one labelled with where it came from and where it is going. These chunks race across the network, often taking completely different roads, and get reassembled perfectly on the other side.

Along the way, these chunks pass through sorting centres. These are buildings full of equipment that reads the address on each chunk and decides which direction to send it next. They do not store Sarah's data. They simply forward it intelligently toward its destination, passing the baton along like a relay race.

Once the chunks arrive at Netflix's building, Netflix reads Sarah's request and prepares a reply. That reply is the actual Netflix homepage: all the images, all the text, all the buttons, and all the styling that Sarah will see on her screen. Netflix cuts that reply into chunks too and sends it all the way back through the same postal network. The chunks travel back through sorting centres, back through Sarah's postal company, back to her house, and reassemble in her browser. Her screen lights up with the Netflix homepage.

And who owns all the trucks, roads, and sorting centres that make this entire postal network run? That is her ISP, her internet service provider. Companies like Vodacom, MTN, AT&T, or BT maintain the physical infrastructure. They own the cables under the streets, the towers on the hills, and the undersea cables crossing ocean floors. When Sarah pays her monthly internet bill, she is essentially paying the postal company to use their roads.

Visualising the Journey: The Analogy Diagrams

Let's draw this out so you can see the full picture. These diagrams follow Sarah's journey from typing netflix.com to seeing the homepage light up on her screen, told entirely through the postal analogy.

Diagram 1: Sarah's Full Request Journey (Analogy Flowchart)

What each part means:

Sarah is our person. She is sitting at her laptop, has opened her browser, typed netflix.com into the address bar, and pressed Enter. That single action kicks off everything else you see in this diagram.

The Phone Book is a lookup service that translates the human-friendly name "netflix.com" into a numerical address that the postal network can actually use. Sarah's browser cannot deliver anything without first knowing the right address, so this is always the very first stop.

The Local Post Office represents Sarah's internet service provider. This is the company she pays every month for internet access. All of her data enters and exits the wider internet through this provider's infrastructure.

Sorting Centre 1 and Sorting Centre 2 are relay points along the route. These are pieces of equipment scattered across the internet whose only job is to look at the address on each piece of data and decide which direction to forward it next. There are often many more than two of these along any given route, but two are shown here to represent the chain.

The Netflix Building is Netflix's server. This is a powerful computer located in a data centre somewhere in the world. It receives Sarah's request, understands what she is asking for, and prepares a response containing the full Netflix homepage.

The return journey follows the same path in reverse. Netflix sends the homepage data back through sorting centres and Sarah's post office until it arrives at her device.

Sarah's Screen is where the magic becomes visible. Her browser takes all the pieces it has received, assembles them in the correct order, and renders the Netflix homepage exactly as the designers intended it to look.

Diagram 2: Sarah's Full Request Journey (Analogy Sequence Diagram)

This second diagram shows the same journey but as a conversation between the different participants, so you can see who talks to whom and in what order.

What each part means:

Sarah initiates everything. She is the one asking the question that sets the entire chain in motion. Without her pressing Enter, nothing in this diagram would happen.

The Phone Book answers Sarah's first question before any real data is sent. It receives the name "netflix.com" and returns a numerical address. This step happens before the letter is even written, because you cannot address an envelope without knowing where it is going.

The Post Office (ISP) is Sarah's gateway to the wider internet. Every piece of data she sends or receives passes through here. Think of it as the front door to the global postal network.

The Sorting Centres represent all the relay points in between. In reality there could be ten, twenty, or even thirty of these between Sarah and Netflix. They pass the data along in a chain, each one making a quick decision about the best next step toward the destination.

The Netflix Building receives the request, processes it, and sends back all of the data that makes up the Netflix homepage. It is not just sending one thing. It is sending the HTML structure, the CSS styling, the JavaScript code, all the images, and the fonts, all of which together create the page Sarah will see.

The note at the bottom is the final moment where everything comes together. Sarah's browser has been collecting and numbering all the incoming pieces, and once they have all arrived it assembles them in order and paints the Netflix homepage onto her screen.

Now Let's Get Technical

"Now that you have the idea, let's connect what you just learned to the real terms engineers use. Don't worry — you already understand this, we're just giving it its proper name."

The Real Words Behind the Analogy

Everything you just read about postal networks, phone books, and sorting centres is real. It is just dressed up in everyday language. Now let's put the proper labels on each part, one by one, and connect each one back to the story of Sarah loading Netflix.

Sarah's "House Address" Is Called an IP Address

Every device connected to the internet has a unique numerical label called an IP address, which stands for Internet Protocol address. It looks something like 192.168.1.1 for devices on a local home network, or something like 54.230.10.1 for a publicly accessible server. The "Internet Protocol" part refers to the agreed-upon set of rules that governs how these addresses are structured and used across the entire internet.

There are two versions currently in use. The older version is called IPv4 and uses four groups of numbers separated by dots, like 142.250.80.46. The newer version is called IPv6 and uses a longer format that includes both numbers and letters, like 2607:f8b0:4004:c07::65. IPv6 was introduced because the world started running out of IPv4 addresses, and given how many devices are now connected to the internet that was not a surprise.

Sarah's laptop has an IP address. Netflix's server has an IP address. Every device in between has one too. Without IP addresses, data would have no way of knowing where to go.

The "Phone Book" Is Called the DNS

The DNS, which stands for Domain Name System, is the internet's global directory service. When Sarah types netflix.com, her browser does not actually know where Netflix is located. It needs to ask a DNS resolver, which is a server whose entire job is to translate human-friendly names like netflix.com into machine-friendly IP addresses like 54.230.10.1.

This lookup happens in milliseconds, completely invisibly, every single time anyone visits a website. Without the DNS, every person on earth would need to memorise long strings of numbers to visit their favourite sites. The DNS is the reason the internet feels human and approachable rather than like a spreadsheet of numbers.

The "Pieces of a Letter" Are Called Packets

Data on the internet is never sent as one continuous stream. It is broken into small, manageable chunks called packets. Each packet contains a small portion of the actual data along with a header, which is a label attached to the front of each packet. That header contains the sender's IP address, the recipient's IP address, and a sequence number so the receiver knows how to put all the pieces back together in the right order.

The system that governs how packets are created, addressed, sent, and reassembled is called TCP/IP, which stands for Transmission Control Protocol over Internet Protocol. TCP is the set of rules that describes how letters must be labelled, what to do if one goes missing, and how to confirm that everything arrived correctly. IP is the addressing system that describes how addresses are structured and used.

If a packet gets lost along the way, TCP notices because the sequence numbers will not add up on the receiving end. It then automatically requests that the missing packet be sent again. This is why your downloads arrive intact and not corrupted even when travelling halfway around the world.

The "Sorting Centres" Are Called Routers

The equipment at those relay points along the route is called routers. A router's entire job is to read the destination IP address printed on the front of each incoming packet and forward that packet in the right direction, a little closer to where it needs to go. Your home internet box, the device your ISP gave you when you signed up, is actually a small router. It routes data between the devices in your home and the wider internet outside.

Large internet routers located in data centres and network hubs around the world handle billions of packets per second. Each one makes split-second decisions about the best path forward, based on constantly updated maps of the network called routing tables. When one path is congested or broken, routers automatically choose an alternative route, which is part of why the internet is so resilient.

Sarah's "Postal Company" Is Called an ISP

Sarah's ISP, which stands for Internet Service Provider, is the company that connects her home to the global internet infrastructure. ISPs own or lease physical infrastructure including fibre optic cables buried under streets, copper telephone lines, mobile towers, and undersea cables crossing ocean floors. All of Sarah's data physically travels through this infrastructure.

When Sarah's internet is "down," it almost always means there is a break or fault somewhere in that physical chain between her home and her ISP's network. The internet itself is almost certainly still running perfectly. The problem is that Sarah cannot reach it.

The "Language on the Letter" Is Called HTTP and HTTPS

When Sarah's browser and Netflix's server communicate, they speak a shared language called HTTP, which stands for HyperText Transfer Protocol. This is the agreed-upon set of rules that defines how a browser asks for a webpage and how a server responds. When Sarah's browser sends its request to Netflix, it uses HTTP to say "Please give me your homepage." When Netflix responds, it uses HTTP to say "Here it is, along with all the files you need to display it."

The version you will almost always see today is HTTPS, where the S stands for Secure. HTTPS adds a layer of encryption to the conversation using a system called TLS, which stands for Transport Layer Security. What this means in practice is that even if someone intercepted Sarah's packets as they crossed the network, they would not be able to read them because the contents are scrambled. That small padlock icon in your browser's address bar means HTTPS is active and your conversation with the server is private.

"Sarah's Device" Is the Client and "The Netflix Building" Is the Server

In technical language, when Sarah requests a webpage her device is acting as a client. The client is the one that makes requests. The computer at Netflix that stores and serves up the webpage is a server. The server is the one that fulfils requests. This relationship is called the client-server model and it is the fundamental architecture of the entire web.

Netflix's servers are not regular laptops. They are extremely powerful computers housed in large, temperature-controlled buildings called data centres, running continuously around the clock. When you load Netflix, you are talking to one of those machines.

The Same Journey With Proper Labels

Here are the same diagrams as before, but now every label uses the real technical terminology. If you compare them to the analogy diagrams above, you will see that the shape of the journey is identical. Only the names have changed.

Diagram 3: The Full Technical Journey (End-to-End Flowchart)

What each part means:

Sarah is the client who initiates everything. Her browser is the software that will handle every part of this process on her behalf, from the DNS lookup to the final rendering of the page.

The DNS Resolver receives the domain name netflix.com and returns the corresponding IP address. Without this step, Sarah's browser would not know which server to contact. This step happens before a single packet of page data is sent.

The ISP Gateway is the physical entry point to the internet. All of Sarah's traffic flows through her ISP's infrastructure. The gateway is the border between her home network and the global internet.

Router 1 and Router 2 represent the chain of routers that sit between Sarah's ISP and Netflix's data centre. Each router reads the destination IP address on each packet and decides which direction to forward it next, based on its routing table. The actual number of routers in a real journey varies but is commonly between ten and thirty.

The Netflix Web Server is the machine that receives Sarah's HTTP request, processes it, and assembles the response. The response includes the HTML file that defines the structure of the homepage, the CSS files that define how it looks, the JavaScript files that make it interactive, and the images and icons that appear on screen.

The return journey sends all of those files back through the same chain of routers and through Sarah's ISP to her device. Each file is broken into packets and each packet travels independently, possibly via different routes.

Sarah's Browser is the final piece of the puzzle. It has been collecting all the incoming packets, using the TCP sequence numbers to put them back in the right order, and once all the files have arrived it reads the HTML, applies the CSS styling, runs the JavaScript, and paints the Netflix homepage on Sarah's screen. Everything she sees was assembled locally on her own device from the files the server sent.

Diagram 4: DNS Resolution in Technical Detail

This diagram zooms in on the DNS lookup step and shows the full conversation that happens before any page data is sent. It looks more complex than it is, and the explanation below will walk you through every step.

What each part means:

Sarah's Browser does not know how to find Netflix on its own. The very first thing it does after Sarah presses Enter is ask a DNS resolver for help. It sends one question: what is the IP address for netflix.com?

The DNS Resolver is a server, usually operated by Sarah's ISP or by a public service like Google or Cloudflare, that handles DNS lookups. It does the detective work on Sarah's behalf by asking several other servers until it finds the answer. Once it has the answer it sends it back to Sarah's browser and also caches it for a period of time, so that the next person who asks for netflix.com gets the answer immediately.

The Root Name Server is at the top of the DNS hierarchy. There are thirteen sets of root name servers distributed around the world. They do not know the address for every website. Instead, they know which servers are responsible for each top-level domain such as .com, .org, or .net. The resolver asks the root server "who handles .com domains?" and the root server points the way.

The TLD Name Server handles one top-level domain. The .com TLD server knows which name server is authoritative for every .com domain. It does not know Netflix's IP address directly, but it knows which server does and it points the resolver there.

Netflix's Authoritative Name Server is the final authority for netflix.com. This server is operated by Netflix and contains the definitive, up-to-date IP address for their website. When the resolver asks it for the IP address, it responds with the answer and the chain is complete.

Once Sarah's browser has the IP address 54.230.10.1, it can finally contact Netflix's server directly and ask for the homepage. This entire DNS conversation typically completes in under 50 milliseconds and is completely invisible to Sarah.

Diagram 5: The Complete End-to-End Technical Sequence

This final diagram shows the entire journey from Sarah pressing Enter to Netflix appearing on her screen in one continuous sequence. This is the full picture.

What each part means:

The DNS lookup is always the first step. Sarah's browser cannot send a single byte of real data to Netflix without knowing the IP address first.

The TCP connection is the handshake that happens before any page data is exchanged. Sarah's browser and Netflix's server agree to talk to each other, confirm they can hear each other, and establish a reliable channel. If the website uses HTTPS, a TLS encryption handshake also occurs here, which is what enables the secure, encrypted connection.

The HTTP GET request is Sarah's browser formally asking Netflix for the homepage. GET is an HTTP method that means "please give me this thing." The request also includes information like what browser Sarah is using and what language she prefers, so Netflix can tailor the response appropriately.

Netflix's response is not a single file. It is a collection of files that together make up the homepage. The HTML file tells the browser what content exists and how it is structured. The CSS files tell the browser how everything should look, including colours, fonts, and layout. The JavaScript files add interactivity, like the hover effects and the play buttons. All of these files are broken into TCP packets and sent back to Sarah.

The browser rendering step at the bottom is what actually creates the visual experience. Sarah's browser reads the HTML from top to bottom, fetches any additional resources it discovers like images and fonts, applies all the CSS rules, and runs the JavaScript. The result is the Netflix homepage appearing on Sarah's screen, usually within a second or two of her pressing Enter.

Frequently Asked Questions

Is the internet the same as the World Wide Web?

No, and this distinction surprises a lot of people. The internet is the global infrastructure: the physical cables, routers, servers, and protocols that allow any computer to communicate with any other computer. The World Wide Web, or just "the web," is one service that runs on top of that infrastructure. The web is the system of webpages and websites that you access through a browser using HTTP or HTTPS.

Think of it this way. The internet is the road network that spans the entire globe. The web is one type of vehicle that uses those roads. Email, video calls, online gaming, file transfers, and streaming apps are all other types of vehicles. They all use the internet's roads but none of them are the same thing as the web.

What actually happens in the second after I press Enter on a website?

Quite a lot happens very quickly. Your browser first asks a DNS resolver for the IP address of the site you want to visit. The DNS resolver returns that address, often from its cache so it is almost instant. Your browser then opens a TCP connection to that IP address and, for HTTPS sites, performs an encryption handshake to secure the channel. Once the connection is established, your browser sends an HTTP GET request asking for the homepage. The server responds by sending back all the HTML, CSS, JavaScript, and image files that make up the page. Your browser receives all of those files, assembles them, and renders the page on your screen. The entire process typically takes between 200 milliseconds and two seconds.

Is the internet stored somewhere physical? Does it live in "the cloud"?

Yes, the internet is entirely physical, and this is one of the most common misconceptions worth clearing up. It runs through an estimated 1.3 million kilometres of undersea fibre optic cables crossing ocean floors, plus countless cables buried under roads, strung between telephone poles, and transmitted through the air via mobile towers and satellites.

"The cloud" is a marketing term for servers, which are real physical computers located in data centres around the world. When you save a photo to iCloud or Google Drive, it physically lives on a hard drive inside a building somewhere. Nothing about the internet is magic or invisible. It is just infrastructure that most of us never have occasion to see.

What is the difference between WiFi and the internet?

WiFi and the internet are two completely different things that often get confused because they are usually used together. WiFi is a short-range wireless technology that connects your device to your local router. It typically reaches about 30 to 50 metres. Think of WiFi as the short path from your sofa to the front door of your house.

The internet is everything beyond your front door, the entire global network. Your router acts as the gateway between your local WiFi network and the wider internet. This means you can have WiFi without internet access, which happens when your ISP connection is down even though your router is switched on and broadcasting. You can also have internet access without WiFi, like when you use mobile data on your phone. The two technologies are related but they are not the same thing.

You Now Understand Something Most People Never Think About

The next time someone says "bad internet," you will know exactly what they mean and more importantly you will understand why. A packet took too long to reach its destination. A router made a suboptimal forwarding decision. The DNS lookup was slow. The Netflix server was overloaded. These are not mysteries anymore. They are just the postal system having a bad day.

You now understand that the internet is a global network of physical infrastructure, governed by agreed-upon protocols, that allows any device in the world to find and communicate with any other device. It does this by translating human-friendly names into IP addresses through the DNS, breaking information into packets, addressing each packet with the sender's and recipient's IP addresses, routing those packets through a chain of routers, and reassembling them at the destination where a browser turns them into the visual experience you actually see on screen.

That is not a simple thing. It is one of the most complex and remarkable engineering achievements in human history. And now you understand it. Welcome to the club.

Found this helpful? Share it with someone who has always wondered but never asked. And if you want to go deeper, our next post explores how HTTPS actually keeps your personal data safe as it crosses the internet.