OSI and TCP/IP layers

The 7-layer OSI model, the 4-layer TCP/IP model, and how they line up with real protocols.

1. 1.The OSI model — seven layers, one mental model

   12 min · Take the quiz

2. 2.TCP/IP — the four-layer model that actually runs the internet

   8 min · Take the quiz

3. 3.Encapsulation — headers all the way down

   8 min · Take the quiz

4. 4.TCP vs UDP — when to use which

   9 min · Take the quiz