# How does the internet actually work? > A straightforward walkthrough of IP addresses, DNS, and routing – the basics that make the internet tick. *Source: https://velstech.net/how-internet-works · Updated: 2026-09-04 · Category: Networking · Tags: Basics, DNS* *Markdown version of [How does the internet actually work?](https://velstech.net/how-internet-works). [Read the full guide with interactive tools](https://velstech.net/how-internet-works).* *Also as Markdown: [Hindi](https://velstech.net/how-internet-works.hi.md) · [Tamil](https://velstech.net/how-internet-works.ta.md).* --- The internet feels like magic, but it's really just three ideas stacked on top of each other: **addressing**, **naming**, and **forwarding**. Understand those, and the whole thing makes sense. ## The mailing analogy Sending data across the internet is like mailing a letter: - IP address = the street address. It uniquely identifies a computer on the network. - Packet = the letter, carrying a chunk of data and the destination address. - Routers = post offices, forwarding each packet toward its destination. - DNS = the phone book, translating names like "velstech.net" into IP addresses. That's 90% of networking right there. Let's look at each piece. ## 1. IP addresses: the addressing Every device on the internet has a unique number – an **IP address**. There are two versions in use: - IPv4 – like 185.199.108.153. Four numbers, ~4.3 billion total. We ran out. - IPv6 – like 2606:4700:4700::1111. Vastly more addresses, slowly rolling out. Most people never see these because of **NAT** – your home router gives each device a private address (like `192.168.1.5`) and shares one public address with the outside world. All your devices "mail" through the same PO box. ## 2. DNS: the phone book Nobody wants to type `185.199.108.153` into a browser. Instead we type `velstech.net`, and the **Domain Name System** looks up the matching IP address for us. When you type a domain, this happens in milliseconds: - Your computer asks its configured DNS server (usually your router or ISP). - If the answer isn't cached, the server follows a chain: root servers → .net servers → the specific nameserver for velstech.net. - The final nameserver returns the IP address, which gets cached so next time is instant. DNS records have types: `A` points a domain to an IPv4 address, `CNAME` points one domain at another, `MX` handles email. This is why "buying a domain" is really "owning the entry in the DNS phone book." ## 3. Packets and routing: the forwarding Your data doesn't travel as one piece. It's chopped into small **packets**, each stamped with source and destination addresses, then sent on its way. Each packet independently hops through **routers** – devices that read the destination and forward the packet toward the right "next hop". Routes can change in real time: if one path is congested or down, packets take another. > Think of it like delivering thousands of pages to a friend by mailing each page > separately. They arrive out of order and via different post offices, but your friend > (the receiving software) reassembles them in the right order. ## The protocols that make it reliable Two protocols do the heavy lifting on top of that raw forwarding: - TCP (Transmission Control Protocol) – guarantees delivery. It numbers packets, detects loss, and retransmits anything missing. Used for web, email, file transfers. Reliable but heavier. - UDP (User Datagram Protocol) – no guarantees, just speed. Fire and forget. Used for video calls, games, DNS. Perfect when a dropped frame is better than a delayed one. ## Putting it together: loading velstech.net - You type velstech.net and hit Enter. - DNS resolves it to 185.199.108.153 (in milliseconds, via cache). - Your browser sends a request split into TCP packets, addressed to that IP. - Routers across the internet forward each packet toward GitHub's servers. - The server responds – its files split into packets and sent back the same way. - Your browser reassembles the packets and renders the page. Total round trip: often under a hundred milliseconds. Hundreds of routers, thousands of packets, and a phone book lookup – all before you finish blinking. ## Why it matters to you Networking knowledge stops being abstract the moment you buy a domain, run a home server, or debug "why is the internet slow". These three ideas – IP addresses, DNS, and packet routing – are the foundation of every connected thing you'll ever set up. 🌐 Try the VelsTech CIDR / Subnet Calculator Need the network address, usable hosts, or broadcast for an IP/prefix combo? Get the whole breakdown in seconds. [Open calculator →](https://velstech.net/cidr-calculator) ## FAQ **What is the difference between an IP address and DNS?** An IP address is the street address of a computer (like 185.199.108.153). DNS is the phone book that translates names like velstech.net into those addresses, so you never have to remember numbers. **What actually happens when I type a website address?** Your computer asks a DNS server for the site's IP. If it isn't cached, the query follows a chain – root servers, then the .net servers, then the domain's nameserver – which returns the IP in milliseconds, and it gets cached for next time. **Why are there two versions of IP addresses?** IPv4 has only about 4.3 billion addresses and we ran out, so devices share one public address through your home router (NAT). IPv6 has a vastly larger pool and is rolling out slowly. --- *VelsTech – technology explained for everyone. Original: https://velstech.net/how-internet-works*