The internet is basically a giant, messy, global “mail system” for data, built out of millions of smaller networks that all agree to speak the same language (protocols).

Quick Scoop: What actually happens

When you “go on the internet” (say, to open a website), this is the simplified chain of events:

  1. Your device connects
    • Your phone/laptop connects to a router (Wi‑Fi box, mobile network, etc.).
    • That router connects to your ISP (Internet Service Provider), like a highway on‑ramp.
  1. You ask for something (a URL)
    • You type www.example.com and hit Enter.
    • Your browser sends a request out through your ISP towards the internet.
  1. Names become numbers (DNS)
    • Computers don’t really use names like google.com, they use IP addresses, which are numbers like 142.250.72.36.
    • DNS (Domain Name System) is like the internet’s phone book: it translates the name into the correct IP address.
  1. Data gets chopped into packets
    • Your request and the website data are broken into small pieces called packets.
    • Each packet has a header (like an address label) plus the payload (the actual content).
  1. Packets travel through many stops
    • Packets hop through routers and switches owned by ISPs and backbone providers.
    • Each router looks at the destination IP and forwards the packet to the next best hop, like a mail sorting center.
  1. The server answers
    • The packets reach the destination server (where the website lives).
    • The server sends response packets back with the HTML, images, CSS, JavaScript, etc.
  1. Your browser rebuilds everything
    • Your device receives packets, reorders and reassembles them into the original files using TCP.
    • The browser parses the HTML, loads CSS and JavaScript, calculates layout, and paints pixels on your screen.

All of this usually happens in under a second.

The core ideas: packets and protocols

Packets: tiny data envelopes

  • Every file, message, or video is split into many packets.
  • Each packet includes:
    • Source IP (where it came from)
    • Destination IP (where it’s going)
    • Other control info (like sequence numbers)
  • Different packets from the same page can take different routes through the world and arrive out of order; your device reassembles them.

Why this is smart:

  • The network can route around broken lines or congested paths.
  • Many people can share the same cables at once, instead of one person monopolizing an entire line.

Protocols: shared rulebooks

Key protocols that make the internet actually work:

  • IP (Internet Protocol):
    • Handles addressing and routing of packets between networks.
  • TCP (Transmission Control Protocol):
    • Ensures packets arrive reliably, in order, and without corruption (retransmits if needed).
  • UDP (User Datagram Protocol):
    • Faster but less strict; used for streaming, gaming, and calls where speed matters more than perfection.
  • HTTP / HTTPS (HyperText Transfer Protocol):
    • Defines how browsers and web servers structure requests and responses for web pages and APIs.
  • Ethernet / Wi‑Fi:
    • Describe how bits move over a local link like your home network.

What really happens when you open a website

Think of typing https://example.com and pressing Enter. Here’s the “movie,” step by step:

  1. Browser checks cache
    • It looks to see if it already has the page or DNS result stored locally.
  2. DNS lookup
    • If not cached, it asks DNS resolvers (often via your ISP) for the IP address of example.com.
    • The resolver may query a hierarchy of DNS servers until it finds the authoritative source.
  1. TCP handshake
    • Your device opens a TCP connection with the server’s IP (three‑way handshake: SYN, SYN‑ACK, ACK).
    • This sets up a reliable channel, agreeing on basics like sequence numbers.
  1. TLS handshake (for HTTPS)
    • Your browser and the server negotiate encryption keys.
    • They verify certificates so you know you’re talking to the real site, not an impostor.
  1. HTTP request
    • Browser sends an HTTP request, something like:
      • Method: GET
      • Path: /
      • Headers: info about your browser, accepted formats, cookies, etc.
  1. Server processes and responds
    • The server runs application code (PHP, Node.js, Python, etc.), hits databases, and generates HTML.
    • It returns an HTTP response with a status code (like 200 OK), headers (cache info, content type), and a body (HTML).
  1. Browser parses and builds the page
    • It parses HTML into a DOM tree.
    • Downloads CSS, builds a CSSOM (style rules).
    • Combines DOM + CSSOM into a render tree, computes layout, and paints pixels.
 * Then it executes JavaScript, which can request even more resources.

The final website you see is the result of many such HTTP requests and responses, each with their own packets and routes.

The physical side: wires, signals, and hardware

Underneath all the software, the internet is very physical.

  • Mediums
    • Copper cables (DSL, Ethernet).
    • Fiber‑optic cables under streets and oceans, carrying light pulses.
    • Radio waves for Wi‑Fi and mobile networks.
  • Devices
    • Routers: decide where to send packets next.
    • Switches: forward packets within a local network.
    • Modems: translate between your home network and the ISP.

Bits are just changes in voltage, light, or radio signals; protocols give those bits meaning.

Why it doesn’t all fall apart

The internet looks chaotic, but it stays usable thanks to design choices.

  • Decentralization
    • No single “master” computer; there are countless independent networks that agree on core protocols like TCP/IP.
  • Redundancy
    • Many paths exist between major points; if one fiber link is cut, traffic can route another way.
  • Scalability
    • IPv4 provided about 4.3 billion addresses; IPv6 adds an enormous address space for essentially unlimited devices.
  • Robust routing
    • Routers exchange information (via routing protocols) so each can pick reasonable next hops for packets.
    • Packets can take different paths and still be reassembled correctly.

“Latest news” and forum‑style takes

People still explain “how the internet actually works” in casual, analogy‑heavy ways, especially on Q&A communities. A common analogy compares it to:

  • Phones:
    • IP addresses ≈ phone numbers,
    • DNS ≈ contact list,
    • Routers ≈ telephone exchanges.
  • Postal mail:
    • Packets ≈ envelopes, each with a destination address.
    • Routers ≈ sorting centers that just look at the address and forward mail closer to its target.

Modern discussions also emphasize encryption (HTTPS everywhere) and performance issues like latency for video calls, gaming, and streaming, which rely more heavily on UDP and content delivery networks.

Information gathered from public forums or data available on the internet and portrayed here.