The internet connects billions of devices across the globe, but most people have no idea what's actually happening behind the scenes. This guide breaks down how data travels from one point to another, in plain English.
Publish date: 2/25/2026
You type a URL into your browser, hit enter, and a webpage loads in under a second. It feels like magic, but there's a lot going on under the hood.
Packets of data are flying across continents, routers are making split-second decisions, and dozens of systems are working together so you can watch a YouTube video or send an email.
Understanding how all of this fits together isn't just interesting, it's genuinely useful if you work with servers, networks, or anything web-related.
Let's walk through it from the ground up.
The internet isn't one single network owned by one company or government. It's a massive collection of interconnected networks, run by internet service providers (ISPs), universities, governments, corporations, and hosting providers, all agreeing to talk to each other using common standards.
At the physical layer, this means fiber optic cables running under oceans, copper wiring in neighborhoods, and wireless signals bouncing off towers. At the logical layer, it means protocols, which are basically agreed-upon rules for how data is formatted, addressed, and delivered.
The combination of these physical and logical layers is what lets a laptop in Tokyo communicate with a server in Amsterdam in milliseconds.
Most people picture the internet as something wireless, living in the cloud. In reality, the vast majority of international internet traffic travels through submarine cables, bundles of fiber optic strands laid along the ocean floor connecting continents to each other.
There are hundreds of these cables in operation today, stretching hundreds of thousands of kilometers across the Atlantic, Pacific, and Indian Oceans. A single modern cable system can carry dozens of terabits of data per second. When you send an email from New York to London, there's a very real chance the data physically traveled along the seabed to get there.
These cables are owned and funded by consortiums of telecoms, ISPs, and increasingly by large technology companies that have invested heavily in their own private cable infrastructure. They land at coastal cable stations, where the signal is amplified and handed off to terrestrial networks for the last stretch of the journey inland.
Submarine cables are also surprisingly vulnerable. They get damaged by ship anchors, fishing equipment, and occasionally earthquakes. When a major cable goes down, entire regions can see significant slowdowns or rerouting of traffic until repairs are made, which can take weeks given the logistics of sending a specialized repair ship to the middle of an ocean.
Once data arrives on land, it still needs to find its way from one network to another. That's where Internet Exchange Points (IXPs) come in.
An IXP is a physical facility where different networks come together to exchange traffic directly with each other, rather than routing it through a third-party transit provider. Think of it like a central post office where multiple courier companies drop off and pick up each other's parcels, instead of each one driving to every other company's depot individually.
Major IXPs like DE-CIX in Frankfurt, AMS-IX in Amsterdam, and LINX in London handle enormous volumes of traffic every day, often multiple terabits per second at peak times. By peering at an IXP, networks can exchange traffic more directly, which reduces latency, cuts down on transit costs, and keeps more traffic local rather than routing it across the world unnecessarily.
For end users, IXPs are largely invisible, but they have a real impact on the speed and efficiency of the internet. A well-connected city with a thriving IXP tends to have faster, cheaper internet than one where all traffic has to be routed through a distant hub.
Every device connected to the internet needs an address so that data knows where to go. That's what an IP address is. Think of it like a postal address, but for computers.
There are two versions in use today. IPv4 uses addresses like 192.168.1.1, expressed as four numbers separated by dots. The problem is that IPv4 only supports around 4.3 billion unique addresses, which sounds like a lot until you account for billions of smartphones, laptops, smart TVs, and servers all needing one. That's why IPv6 was developed, using a much longer format that supports a virtually unlimited number of addresses.
Most of the internet today runs on a mix of both, with IPv6 adoption growing steadily.
Humans aren't great at remembering strings of numbers. That's where the Domain Name System (DNS) comes in. DNS is essentially the internet's phonebook. When you type example.com into your browser, your computer asks a DNS resolver, "what's the IP address for this domain?" The resolver looks it up and returns something like 93.184.216.34, which your browser then uses to connect to the right server.
This lookup happens in milliseconds, and the results are often cached so it doesn't have to happen every single time you visit the same site.
DNS is one of the most foundational parts of how the internet works, and when it breaks, things go wrong fast.
When you send or receive data over the internet, it doesn't travel as one continuous stream. It's broken up into small chunks called packets. Each packet contains a piece of the data you're sending, plus addressing information so routers know where to deliver it.
The protocols that govern this are TCP/IP, which is really two separate things working together.
IP (Internet Protocol) handles addressing and routing. It decides how packets are labeled and where they should go.
TCP (Transmission Control Protocol) handles reliability. It makes sure packets arrive in the right order, and if any are lost along the way, it requests them again. This is why downloading a file doesn't result in a corrupted mess even if a few packets drop.
For things where speed matters more than perfect accuracy, like live video streaming or gaming, a lighter protocol called UDP is often used instead. UDP doesn't bother with re-requesting lost packets, which keeps latency lower.
Packets don't travel in a straight line from point A to point B. They hop through a series of routers, each one making a decision about where to send the packet next based on its destination address.
Routers maintain routing tables, which are essentially maps of the network. They're constantly updated using routing protocols. For traffic within a single network, protocols like OSPF are common. For traffic between different networks across the internet, the key protocol is BGP, or Border Gateway Protocol.
BGP is sometimes called the "glue of the internet." It's how large networks, called autonomous systems, advertise which IP addresses they're responsible for, so other networks know how to route traffic to them. IXPs are where much of this BGP peering happens in practice, with networks exchanging routing information and traffic directly across a shared switching fabric. When BGP goes wrong, large parts of the internet can become unreachable. It's happened before, and it's a reminder of just how interdependent the whole system is.
Once your browser has the IP address of the server you want to reach, it needs a way to actually request and receive web content. That's where HTTP (HyperText Transfer Protocol) comes in. Your browser sends an HTTP request asking for a specific page, and the server responds with the content.
Most of the web now uses HTTPS, which is HTTP with encryption layered on top via TLS (Transport Layer Security). This means the data traveling between your browser and the server is encrypted, so third parties can't easily intercept and read it. You'll see this indicated by the padlock icon in your browser's address bar.
Getting HTTPS set up on a server used to require purchasing certificates, but today tools like Certbot make it straightforward to get free certificates from Let's Encrypt.
When you request a webpage, something on the other end has to respond. That something is a server, usually sitting in a data center somewhere in the world. Data centers are purpose-built facilities with redundant power, cooling, and network connectivity designed to keep servers running around the clock.
The physical path your data takes to reach that server depends a lot on geography. A request from Singapore to a server in the same city might travel just a few milliseconds. The same request to a server in Europe might take 150ms or more, simply due to the physical distance the light and signals have to travel through cables, including, quite possibly, a submarine cable crossing an ocean.
This is one of the main reasons why businesses choose servers or hosting locations geographically close to their users.
Content Delivery Networks, or CDNs, solve the distance problem by distributing copies of content across many servers around the world. When you load a popular website, there's a good chance you're not getting the content from the origin server at all. You're getting it from a CDN node nearby.
CDNs are especially useful for static assets like images, CSS, and JavaScript files, things that don't change between users. By serving these from a location close to the visitor, load times drop noticeably.
Here's the full picture of what happens when you visit a website, simplified into a sequence:
All of that happens, usually, in well under a second.
The internet is a genuinely impressive feat of engineering, built on layers of open standards and cooperation between thousands of independent organizations, tied together physically by cables on the ocean floor and logically by exchange points where networks shake hands and share traffic. Once you understand the basics, things like DNS outages, latency issues, or TLS errors stop being mysterious and start making a lot more sense.
At xTom, we work with this infrastructure every day. Whether you're running applications in the cloud, connecting your business to the internet, or building something that needs reliable, low-latency connectivity, the quality of your underlying infrastructure matters. xTom offers dedicated servers, colocation, and IP transit services across global data centers, while V.PS provides NVMe-powered scalable KVM VPS hosting for teams that need fast, flexible compute. If you need something more accessible to get started, shared hosting is available too. You can explore the full range of xTom services here.
Ready to discuss your infrastructure needs? Contact our team to explore the right solution for your projects.
The internet is the physical and logical network infrastructure, the cables, routers, servers, and protocols. The World Wide Web is a service that runs on top of the internet, specifically the system of websites and pages you access through a browser using HTTP. Email, FTP, and VoIP are also internet services, but they're not part of the Web.
There are over 600 submarine cable systems either in service or under construction as of the mid-2020s, totaling more than 1.4 million kilometers of cable. Ownership is typically shared between consortiums of ISPs and telecoms, though companies like Google, Meta, and Microsoft have increasingly funded and built their own dedicated cable systems to handle their traffic demands.
Traffic gets rerouted automatically through other available cables and paths, though this can increase latency and, in regions with limited cable redundancy, cause noticeable slowdowns. Repair vessels have to locate the fault and splice the cable back together, a process that can take several weeks depending on the location and sea conditions.
An IXP is a physical location where different networks interconnect and exchange traffic directly with each other. Without IXPs, traffic between two networks would have to travel through paid transit providers, adding cost and often extra latency. IXPs make the internet more efficient, more local, and generally faster for end users near them.
Your connection to your ISP might be fine, but speed depends on every link in the chain between you and the server you're trying to reach. Congestion on intermediate networks, a slow or overloaded server, or geographic distance, including how many submarine cable hops are involved, can all cause slowdowns that have nothing to do with your local connection.
Latency is the time it takes for a packet to travel from your device to a destination and back, usually measured in milliseconds. Lower latency means more responsive connections, which matters especially for gaming, video calls, and anything real-time. Even on a fast connection, high latency can make things feel sluggish.
If the DNS resolver your device is using becomes unavailable, you won't be able to resolve domain names into IP addresses, so websites will appear unreachable even if your internet connection and the target servers are both working fine. Using a reliable, redundant DNS resolver helps avoid this. Options like DNS.SB offer privacy-focused alternatives to default ISP resolvers.
An autonomous system (AS) is a large network or group of networks under a single administrative control, like an ISP, a major corporation, or a hosting provider. Each AS has a unique number (ASN) and uses BGP to advertise its IP address ranges to the rest of the internet. The internet is essentially a web of thousands of autonomous systems exchanging routing information with each other, often meeting up to do so at IXPs.
Technically the same protocols are used globally, but in practice the internet experience varies significantly. Some countries filter or block certain content at the network level. Connection speeds and latency differ based on infrastructure investment, and access to submarine cables and IXPs isn't equal across all regions. Countries or islands with fewer cable landing points tend to have less redundancy and can be more vulnerable to outages when a cable is cut.