Notes
Goal: Understand the basics of the Internet—not a magical cloud, but physical wires connecting computers worldwide. Explains clients, servers, DNS, and undersea cables.
Key Concepts
- Internet Basics: Just wires (cables) connecting computers globally. Allows data transfer between any connected devices.
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Clients vs Servers:
- Client: Your computer/phone (requests data).
- Server: Special computers online 24/7 (serve websites/files). Like a giant library open anytime.
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Accessing a Website (e.g., google.com):
- Type domain → Browser sends request to ISP (Internet Service Provider, e.g., Comcast, BT).
- ISP forwards to DNS Server (Domain Name System—like a phone book).
- DNS looks up IP Address (unique “postal code” for every computer/server).
- Browser requests data directly from server’s IP.
- Server sends back files → Page loads.
- Undersea Cables: Massive fiber optic cables on ocean floor connect continents. Use lasers for data (up to 400 GB/s per fiber).
Common Pitfalls / Gotchas
- People think Internet is “in the cloud” → It’s physical infrastructure.
- Data travels at light speed, but via cables (not wireless everywhere).
Connections to Other Topics
- Foundation for web dev: We’ll build sites that live on servers.
- Links to HTTP/HTTPS (next lessons), domains, hosting.
- IP addresses → Later: Servers in Node.js/Express.
To Review / Resources
- Try it: nslookup.io → Find IP for any domain (paste IP in browser).
- Map: submarinecablemap.com → Explore global cables.
Summary: Internet = Global network of cables connecting clients (us) to servers. DNS translates human domains to IP addresses for fast requests. Mind-blowing physical tech powers everything we build!