13. Networking essentials
How computers talk to each other across the internet. A deeper look at concepts touched on in 01-foundations. Not full network engineering — just enough to debug “why isn’t my API responding” or “why is this DNS change taking so long.”
Entries
| # | Entry | Status | One-line description |
|---|---|---|---|
| 1 | IP addresses | 🟩 COMPLETE | The numeric address of every device on the internet — IPv4 vs IPv6 |
| 2 | DNS — deep dive | 🟩 COMPLETE | The phone book of the internet — records, TTLs, propagation |
| 3 | HTTP & HTTPS | 🟩 COMPLETE | The conversation format of the web — methods, status codes, headers |
| 4 | TCP vs UDP | 🟩 COMPLETE | Reliable-and-slow vs fast-and-fire-and-forget |
| 5 | Ports | 🟩 COMPLETE | What :3000, :80, :443 actually mean |
| 6 | WebSockets | 🟩 COMPLETE | Persistent two-way connections — for live data, chat, multiplayer |
| 7 | Webhooks — deep dive | 🟩 COMPLETE | The reverse-request pattern, plus signing/verification |
Suggested reading order
3 → 2 → 1 → 5 → 4 → 7 → 6. HTTP first because it’s what you’ll deal with daily.