The OSI Model: Stop Memorizing Acronyms, Start Understanding Layers
You’ve probably seen the diagram: seven colored boxes stacked vertically with cryptic acronyms—PHY, DLL, NWK, TRM, SES, PRS, APP. If you are like most people learning networking, you memorized them for an exam —or maybe an interview —nodded, and moved on without truly understanding why they exist. Here is the reality: Layers aren’t physical things. They are agreements. They are protocols — a shared understanding between two systems on how to talk to each other. Understanding this distinction changes everything about how you debug, architect, and think about networking. ...