Security engineers use the OSI and TCP/IP models less as networking theory and more as a diagnostic map: when something goes wrong or an attack is detected, the first question is always 'which layer is this happening at?' The seven-layer OSI model separates concerns from physical cabling up through application data, while the four-layer TCP/IP model is the simplified, practically implemented version the internet actually runs on. Knowing both lets an engineer read a packet capture, a firewall log, or an attack report and immediately know which tools and controls are relevant.
Analogy🏏Cricket
💪 Think of it like fitness: injuries follow a predictable chain — poor warm-up, then form breakdown, then compensation, then the actual tear — and a good physio catalogs where each patient's chain can be interrupted early, rather than only treating the tear afterward. MITRE ATT&CK is the sports-medicine literature of intrusions: a public catalog of every observed breakdown pattern, organized by the stage it serves — how attackers get in, how they escalate, how they extract. Coaches worldwide describe an athlete's risk in that shared vocabulary. This reveals ATT&CK's real value: intrusions become a sequence you can interrupt at stage two, not a disaster you discover at stage five.