Beginner22 lectures
Every time you open a browser, stream a video, or send a message, dozens of invisible systems work together in milliseconds to make it happen. This course shows you exactly how.
Starting from the physical layer signals and cables you'll work your way up through the full network stack to the application protocols you use every day. Along the way you'll build genuine intuition for how data actually moves across the internet: how it gets addressed, routed, verified, and reassembled at the other end.
Each unit closes with a Boss Challenge a real-world scenario where you apply what you've learned to debug, design, or trace a complete network interaction.
**What you'll cover:**
- How the internet works: packets, switching, OSI and TCP/IP models
- Physical and link layer: signals, encoding, error detection, Ethernet, switches
- Network layer: IPv4, subnetting, CIDR, routing, ARP, NAT
- Transport layer: ports, sockets, UDP, TCP, the 3-way handshake, flow control
- Application layer: DNS, HTTP/HTTPS, TLS, and real-world protocols
**Who this is for:** Developers who want to understand what happens beneath their API calls, students preparing for networking certifications or CS exams, and anyone who's ever wondered what actually happens when you type a URL.
**Prerequisites:** No networking experience required. Basic familiarity with how computers work is helpful but not mandatory.