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Learning path · 10 parts

How the Internet Grew

The internet told as a chain of inventions — each one solving the exact limit the last success ran into, from raw packets up to the web you are reading this on.

About 2 hours of reading · 20 widgets

Start with Packet Switching
  1. Networks & the Internet10 min

    Part 1: Packet Switching

    Why the internet chops your data into hundreds of independently-routed packets instead of reserving a wire for you, and how that one choice buys both efficiency and resilience.

  2. Networks & the Internet10 min

    Part 2: IP Addresses and Routing

    IP gives every device an address and lets routers forward packets hop by hop toward it — best-effort, connectionless, and with no single router that knows the whole route.

  3. Networks & the Internet10 min

    Part 3: TCP: Reliability on an Unreliable Network

    IP loses, duplicates and reorders packets and promises to fix none of it. TCP turns that mess into a perfect ordered byte stream — entirely at the two endpoints, without ever changing the network in between.

  4. Networks & the Internet10 min

    Part 4: DNS: The Internet's Phone Book

    Humans use names; the network routes to numbers. DNS bridges the gap with a distributed, delegated tree — no single machine holds the whole thing, and caching makes it feel instant.

  5. Networks & the Internet10 min

    Part 5: HTTP and the World Wide Web

    The web is one application running on top of the internet's plumbing. HTTP is how a browser asks a server for a resource — a stateless request and response that cookies and the Host header quietly extend into logins and shared hosting.

  6. Networks & the Internet9 min

    Part 6: NAT: How Billions Share Four Billion Addresses

    There are about four billion possible IPv4 addresses and far more than four billion connected devices — yet everything works. Network Address Translation is the stopgap hiding in every home router that lets a whole network share a single public address, disambiguated by port.

  7. Networks & the Internet10 min

    Part 7: TLS: Encrypting the Web

    Plaintext HTTP let anyone on the path read your passwords. TLS wraps the connection in encryption by using slow asymmetric crypto only to authenticate the server and agree a key, then switching to fast symmetric crypto for the data.

  8. Networks & the Internet10 min

    Part 8: Certificates and the Chain of Trust

    TLS hands your browser a public key and says 'encrypt to me' — but anyone can generate a key. Certificates and a chain of signatures reaching back to a short list of preinstalled authorities are what tie that key to a real identity.

  9. Networks & the Internet10 min

    Part 9: Load Balancers and Reverse Proxies

    One server has a ceiling and a single point of failure. Reverse proxies and load balancers turn many fragile machines into one fast, reliable service by spreading load and health-checking around failures.

  10. Networks & the Internet10 min

    Part 10: CDNs: Bringing the Web Closer

    A load balancer scales a site in one place, but distance sets a floor on latency that no amount of hardware can beat. CDNs scale geographically — caching content at hundreds of edge locations near users, and steering each request to the closest one.