Your device sends a request, routers pass it along, and servers send information back

When you type a web address or click a link, your device doesn't connect directly to the website. Instead, it sends a request through a series of routers — machines that read the address on your request and point it toward the next router, the way a postal worker reads an address and sends a letter to the right distribution center. Each router passes your request closer to its destination until it reaches the server that holds the website. That server reads your request, finds the right files, and sends them back through the same network of routers to your device, which assembles them into the page you see.

This happens in milliseconds. The speed depends on the physical distance your data travels, the number of routers it passes through, and how busy each one is. A request to a server across the country takes longer than one to a server in your city, but still usually arrives in under a second.

Key Takeaways

  • Your device connects to the internet through an Internet Service Provider (ISP), which assigns you a unique address called an IP address so routers know where to send information back to you.
  • Routers read the destination address on each piece of data and forward it to the next router in the path, similar to how mail moves through postal sorting facilities.
  • Servers are computers that store website files and respond to requests by sending those files back to your device over the network.
  • The Domain Name System (DNS) translates web addresses like google.com into IP addresses that routers can actually read and use.
  • Data travels in small chunks called packets, each labeled with where it came from and where it is going, so routers can reassemble them in the right order when they arrive.

Your Internet Service Provider connects you to the larger network

You cannot connect directly to the internet. Instead, you pay an Internet Service Provider — a company like Comcast, Verizon, AT&T, or a local provider — to connect your home or device to their network, which connects to the larger internet backbone. The ISP assigns your device an IP address, a unique number like 203.0.113.45 that identifies you on the network. When a server sends information back to you, it addresses it to that IP address, and the ISP's routers know to send it to your home.

Your ISP also provides a modem (a device that converts the signal from their network into a form your devices can use) and often a router (a device that distributes that connection to multiple devices in your home via Wi-Fi or ethernet cables). The router creates a local network inside your home and assigns each of your devices a private IP address that only works within your home. When your device sends a request to the internet, the router translates that private address into your public IP address so the outside world can send the response back to your home.

Routers read addresses and forward data to the next step in the path

A router is a machine that reads the destination address on a piece of data and decides which direction to send it. When your request leaves your home, it goes to your ISP's router. That router reads the address and forwards it to another router, which might be owned by a different company. That router forwards it to another, and so on, until the request reaches a router that knows the final destination — the server you are trying to reach.

This chain of routers is not fixed. If one router is overloaded or broken, data can take a different path. The internet was designed this way so that no single broken link could shut down the whole system. Each router only needs to know about the routers when ready around it, not about every other router in the world. This is why the internet can keep working even when parts of it fail.

The path your data takes can change from one request to the next. A request to the same website at 9 a.m. might travel through different routers than a request at 10 a.m., depending on network traffic and which routers are available.

The Domain Name System translates web addresses into IP addresses

You type google.com into your browser, but routers cannot read that. They only understand IP addresses — numbers like 142.250.185.46. The Domain Name System (DNS) is a network of servers that translates human-readable web addresses into IP addresses. When you type google.com, your device sends a request to a DNS server asking "What is the IP address for google.com?" The DNS server looks it up and sends back the answer: 142.250.185.46 (or one of Google's other IP addresses). Your device then uses that IP address to request the website from Google's servers.

Your ISP usually provides a DNS server, but you can use a different one. Some people use Google's DNS (8.8.8.8), Cloudflare's DNS (1.1.1.1), or others. The DNS server you use does not change which websites you can reach, but it does log which addresses you look up. This is one reason some people care about which DNS provider they use — it is a small part of your browsing history that is separate from your ISP's logs.

Data travels in small packets, each labeled with its origin and destination

Your device does not send a website as one large file. Instead, it breaks the request and the response into small chunks called packets. Each packet is labeled with the IP address it came from, the IP address it is going to, and a sequence number so the receiving device can reassemble them in the right order. A typical packet is between 1,500 and 65,000 bytes — small enough to move quickly through the network.

When you read a large file, like a video, it arrives as hundreds or thousands of packets. Your device receives them, checks that they all arrived, and reassembles them into the original file. If a packet gets lost on the network, your device can ask for it to be sent again. This system makes the internet reliable even though individual packets can take different paths and arrive out of order.

Packets can be lost or delayed, especially on congested networks or over Wi-Fi. This is why a video might buffer, or why a read might stall and restart. The sending device keeps track of which packets arrived and which did not, and resends the missing ones.

Servers store website files and respond to requests

A server is a computer that runs 24 hours a day and stores the files that make up a website — the HTML code, images, videos, and databases. When your request reaches a server, software on that server reads what you asked for, retrieves the right files, and sends them back to you. If you request google.com, Google's servers send back the HTML code for the search page, the images and styling that make it look right, and the code that makes it interactive.

Large websites like Google, Facebook, or Netflix do not run on a single server. They run on thousands of servers in data centers around the world. When you make a request, a system called a load balancer directs your request to one of those servers — usually the one closest to you, to make the response faster. If one server fails, the load balancer sends your request to another one, so the website stays online.

Servers can also be owned by individuals or small businesses. A small website might run on a single server rented from a hosting company. That server is still a computer in a data center somewhere, running the same way as Google's servers, just handling fewer requests.

Encryption protects data in transit between your device and servers

When you visit a website that starts with https:// (rather than http://), the data between your device and the server is encrypted — scrambled so that only your device and the server can read it. This protects passwords, credit card numbers, and other sensitive information from being read by routers, your ISP, or anyone else on the network between you and the server.

The encryption uses a system called TLS (Transport Layer Security). When you first connect to an https:// website, your device and the server exchange special codes that allow them to encrypt and decrypt messages to each other. After that exchange, everything you send is encrypted before it leaves your device, and everything you receive is encrypted until it reaches your device. Routers can see that data is moving between you and the server, but they cannot read the contents.

Not all websites use https://. Many do not handle sensitive information and do not need it. However, any website where you enter a password, credit card number, or personal information should use https://. You can check by looking at the address bar — a lock icon next to the address means the connection is encrypted.

Your browsing leaves traces at multiple points in the network

Even though encryption protects the contents of your requests, several parties can still see which websites you visit. Your ISP can see the IP addresses you connect to (though not the pages within those sites if they use https://). Your DNS provider can see which web addresses you look up. The websites themselves log your IP address and what you request from them. Your router logs which devices in your home connected to which addresses.

This is not necessarily a problem — it is how the internet is built. But it means your browsing is not completely private, even if individual requests are encrypted. If you want to hide which websites you visit from your ISP, you can use a VPN (Virtual Private Network), which encrypts all your traffic and routes it through a server operated by the VPN company. However, this means the VPN company can see which websites you visit instead of your ISP.

Frequently Asked Questions

What happens if a packet gets lost on the way to my device?

Your device keeps track of which packets arrived and which did not. If a packet is missing after a short time, your device asks the server to send it again. This happens automatically — you do not need to do anything. If many packets are lost, the connection slows down because the server has to resend them.

Can my ISP see what I do on websites if they use https?

Your ISP can see which websites you visit (the IP address and domain name), but not what you do on them. If you visit amazon.com, your ISP knows you visited Amazon, but not which products you looked at or what you bought. The contents of the page are encrypted.

Why do some websites load faster than others?

Speed depends on the distance between you and the server, how busy the routers in between are, how many files the website needs to send, and how fast your internet connection is. Websites that use servers close to you, that compress their files, and that use fewer images usually load faster.

What is the difference between my IP address and my MAC address?

Your IP address identifies you on the internet and is assigned by your ISP. Your MAC address identifies your device on your local home network and is built into your device's hardware. Routers use your MAC address to send data to the right device in your home, and your IP address to send data to your home from the internet.

Do I need to do anything to maintain my connection to the internet?

Usually no. Your ISP maintains the connection automatically. If your internet stops working, restart your modem and router by unplugging them for 30 seconds and plugging them back in. If that does not work, contact your ISP — the problem is likely on their end.