Key Differences between #OSI and #TCPIP Models

Key Differences between OSI and TCP/IP Models

1. Number of Layers:
• OSI Model: Has 7 layers (Application, Presentation, Session, Transport, Network, Data Link, Physical).
• TCP/IP Model: Has 4 layers (Application, Transport, Internet, Network Interface).
• Real-World Example: Imagine assembling furniture. OSI has more detailed steps, like breaking down each screw and part, while TCP/IP combines steps to make the process faster.
2. Purpose and Origin:
• OSI Model: Designed as a theoretical framework to understand data communication in detail, but isn’t strictly used in real-world networks.
• TCP/IP Model: Created as a practical guide for internet communication, making it the standard used on the internet today.
• Real-World Example: OSI is like a full instruction manual for understanding every part of a machine, while TCP/IP is the quick-start guide that gets the job done faster.
3. Layer Functionality:
• OSI Model: Each layer has a distinct function, making it very structured and specific.
• TCP/IP Model: Some layers combine functions from the OSI model (e.g., Application, Presentation, and Session layers are all combined into one Application layer).
• Real-World Example: OSI is like a well-defined assembly line where each worker has a unique task. TCP/IP combines some tasks to make the process simpler and quicker.
4. Implementation:
• OSI Model: Mostly theoretical, used as a guide to understanding network processes.
• TCP/IP Model: Widely used in the real world, especially for internet communication.
• Real-World Example: OSI is like a detailed academic lesson on how an engine works, while TCP/IP is the engine that actually powers your car.

Comparison Table

Aspect	OSI Model	TCP/IP Model
Layers	7 Layers	4 Layers
Use	Theoretical, teaching model	Practical, widely used on the internet
Application Layer	Three separate layers (Application, Presentation, Session)	Combined into one Application layer
Routing and Addressing	Split between Network and Transport Layers	Managed by Internet and Transport Layers
Main Purpose	To understand networking concepts	To provide guidelines for internet data transfer

 Summary

The OSI model is useful for understanding the details of data communication, while the TCP/IP model is what we actually use in the real world for the internet. OSI is like the “textbook” version, while TCP/IP is the “real-world” version.