How does the internet work? It seems like a simple enough question, but it’s a mountain hidden under a molehill. Thankfully, we’re pretty good at this internet stuff here at Pentanet. Over the years, we’ve got a decent enough handle to feel like we can break it down for you. So, let’s talk about what happens when you type in “funny cat videos” on YouTube and how the internet gets those cute kitties to your screen. We’re going to into it pretty deep here, so if your eyes start to glaze over, skip to the bottom for the TL;DR.
The first thing to understand is that the internet is not a single construct. We don’t all connect our computers to some mythical ‘internet fluffy cloud’ hovering in the sky, dispensing cat videos and memes like a benevolent god. No, the internet is an assemblage of thousands upon thousands of interconnected networks, better envisioned as an endless sequence of highways between networks worldwide and roads within those networks to individual devices.
To stop this great internet transit system from turning into total bedlam, requests (in this metaphor, cars) travelling on it follow the rules of the road, Internet Protocol (IP) which are rules governing how information is sent from one computer to another and a list of addresses that tell data where it came from and where it needs to go, and Transfer Control Protocol (TCP) which works alongside IP to ensure transfer of data is dependable and reliable.
When a message (whether that message is data, a file, media, or text) is sent down the internet highway, to make it manageable, it’s broken up into individual packets, like breaking up a delivery into pieces to fit it into the trucks. Once they reach their destination, they’re unwrapped and put back together to reconstruct the message. This is why in the days of dial-up internet, you’d see images made line by line as they load in; that’s the data packets arriving individually.
The nitty gritty
So, now that we’ve laid the field let’s see how we get those cat videos to your door.
Your device is connected to the internet through a router (and modem depending on connection type). Think of the router as your device’s road to your internet service provider’s servers. Where a modem is required, its job is to convert a signal received through a copper line into data devices can process. When you type in a URL (A Uniform Resource Locater), it sends a query through your modem to your ISP, which stores and then sends data through its DNS (Domain Name Server) servers. Your browser uses these DNS servers to translate the URL you input into the number-based IP address; you can think of them as a directory or a road map.
It then sends a Hypertext Transfer Protocol (HTTP) request (Or an HTTPS request, which is the secure encrypted version) through your ISP, onto the internet highway, to the server associated with this IP address (for example, google.com’s IP address is 18.104.22.168). The server parses this request and sends back the web page files needed to create your YouTube video as a series of packets, which your browser reassembles into a complete package.
The request and the data get wrapped in identifiers at each step of this journey. Think of these as the sender address and the return address. When your device sends the request to the modem, it tells the router which device it came from, then your modem tells the ISP’s servers which modem it came from, then when the ISP’s servers send it off to a different server to fetch the data, it tells it which server it came from.
Then when the data returns, these wrapped addresses are unwrapped one by one to ensure the data packets end up in the same place the request came from. After all, it’d be pretty embarrassing if you tried to look up cat videos and they wound up on your boss’s computer on the same network. These wrapped addresses are all part of the Internet Protocol (IP), ensuring data ends up where it needs to go; without these protocols, data would take far longer to find its way and could go nowhere at all or somewhere completely different.
When you request information (such as a webpage) over the internet, your device sends this request to your router, which passes it off to your ISP’s servers. From here, these servers locate the destination, and send it on its way, then the process is repeated in reverse to get it back to you. Each step of the way, an address is appended to the request to help find its way home, and not get lost in the aether. Large requests will be broken up into packets of information, then reassembled (like you’re building IKEA furniture) once they reach their destination, which is what’s happening if you ever see a webpage slowly loading in.
So, there you have it, a basic guide to getting where you need to go on the net. Want to learn more about how the internet works? Check out our glossary of internet terminology here and a guide to how latency affects your internet experience here, as well as tips for staying safe online here. If you want a next-level internet connection you can rely on, well, you're in the right place. Head to our homepage to enter your address and see what connections are available in your area.