The internet is a global network of interconnected computers that communicate using standardized protocols. When you simply type a website in and go to it, a lot happens in the background that many people don’t understand how it works. This blog will give you a basic understanding of how the internet works. From typing in a URL in the address bar to where that goes and how that gets there and back.
When you open a browser and go to a website it first uses something called Domain Name System (DNS). DNS is like a phone book of the internet. It converts human readable domain names into machine readable IP addresses. Sometimes a domain may resolve to multiple IP addresses depending on how the website is set up. Once the IP is known, your device sends a request to that server using either HTTP or HTTPS. HTTP is not safe while HTTPS uses Transport Layer Security (TLS) to encrypt the communication between your device and the server. This protects your data from being intercepted or tampered with, which can happen in attacks called man-in-the-middle.
Your data travels from your computer to your default gateway, which is usually your router, to an ISP, often routing it through Internet Exchange Points (IXPs) or transit providers, and then to the destination server. Internet Exchange Points are physical locations where different networks connect and exchange traffic efficiently. Transit providers are companies that carry internet traffic between networks when direct connections do not exist. Not all traffic goes through IXPs, but ISPs are often connected to them or to transit providers and backbone networks to route traffic efficiently to and from its destination. Once your request has been received by the server, the server will then send a response back to your computer.
The data travels in small units called packets which are routed through routers, ISPs, and other parts of the internet infrastructure. These devices determine the most efficient path to get to your destination server. On a global scale, devices like routers use a routing protocol called Border Gateway Protocol (BGP). Internal routing inside an ISP or local network might use different protocols like OSPF. Data will sometimes have to cross continents which are very long distances. This involves sending the data undersea with massive fiber-optic cables. These fiber-optic cables lie on the ocean floor and form the backbone of global internet communication. These cables can transmit terabits of data per second and are very critical to maintaining fast internet speeds. If these cables were to be damaged or cut you could have significantly worse internet or no internet at all depending on if there is even another alternative route that can be used or not.
During this process your packets might be inspected, rerouted, or even delayed depending on network congestion, firewall rules, or security checks. Once they reach the destination server which is usually housed in a data center, the server processes your request and sends the response back in packets. These packets might take a different route on the way back, but they are all reassembled by your device using the Transmission Control Protocol (TCP), which ensures they arrive correctly and in order.
The TCP/IP stack is a set of communication protocols used to connect devices on the internet. It has four layers which are Application, Transport, Internet, and Network Access or sometimes referred to as Link. Each layer handles specific tasks like the Application layer managing protocols such as HTTP and DNS, while the Transport layer uses TCP or UDP to ensure data delivery. Together, these layers allow data to move reliably and efficiently from one computer to another across networks.
Large websites often use Content Delivery Networks (CDNs) to deliver content faster by storing cached versions of data on servers located closer to the user. By doing this you are reducing the distance that needs to be traveled in the network which speeds up travel and load times. Your device uses MAC addresses at the hardware level and IP addresses at the network level to identify itself and communicate over the internet. MAC addresses are only used within your local network and do not travel over the internet.
Modern internet infrastructure includes firewalls, routers, switches, intrusion detection systems (IDS), intrusion prevention systems (IPS), load balancers, data centers, security protocols, and other technologies. While components like firewalls and security protocols help ensure that only authorized users can access certain data, data centers provide the physical and virtual resources needed to store, process, and deliver that data. Businesses, governments, and individuals all rely on this infrastructure daily for activities such as browsing, email, streaming, gaming, and remote work.
The internet is decentralized, meaning no single organization controls it. Instead, it operates through a global system of standards, organizations, and agreements. Organizations like Internet Corporation for Assigned Names and Numbers (ICANN) help manage domain names and IP address allocation. There are many other important organizations as well like Internet Assigned Numbers Authority (IANA) that operate under ICANN and are responsible for coordinating the global allocation of IP addresses, managing the DNS root zone, and assigning protocol parameters. Some other organizations are Domain Registrars. These are accredited by ICANN. Companies like GoDaddy, Namecheap and many more sell and manage domain names for end users. These organizations work together to maintain a stable, secure, and interoperable internet by managing the allocation and registration of domain names and IP addresses.
In summary, the internet is a very large, complex system of physical infrastructure, logical protocols, and software layers. This large, complex system is managed by many technical professionals with their own areas of expertise to ensure the internet remains operational and efficient. The internet allows users across the globe to exchange information efficiently through a combination of DNS resolution, IP routing, encrypted communication, and massive backbone networks like undersea cables and IXPs. All these components working together allows people to load a webpage, send a message, play video games online, or watch a video. It is one of the best inventions in my opinion because it is so much more. It allows people to connect worldwide and allows for many possibilities like furthering education, collaboration or connecting communities that before were either difficult to connect or impossible to connect.