Which model was developed by ISO after the TCP/IP model to provide greater granularity?

• A. TCP/IP model
• B. OSI model
• C. Hybrid model
• D. Internet model

Answer: (B)

The main idea is that the OSI model provides a detailed, standardized framework for how network communications should happen. Created by ISO after TCP/IP, it adds more granularity by splitting functions into seven distinct layers, from physical up to application. This separation, especially with the inclusion of session, presentation, and application layers, makes responsibilities clearer and defines precise interfaces between layers. OSI is a reference model meant to guide interoperability and understanding, not a single protocol suite you deploy, unlike TCP/IP. This structure lets you reason about where a given function belongs and how changes in one layer affect others, promoting easier troubleshooting and network design through well-defined boundaries.