The TCP/IP Model is a practical networking model developed by DARPA and used in the real Internet.
It defines how data is transmitted across networks.
| Layer | Function |
|---|---|
| Application | User services (HTTP, FTP, DNS) |
| Transport | End-to-end communication (TCP/UDP) |
| Internet | IP addressing & routing |
| Network Access | MAC addressing & physical transmission |
🔝 Application Layer
Combines OSI Application + Presentation + Session
🚚 Transport Layer
Uses TCP (reliable) and UDP (fast)
Uses port numbers
🌍 Internet Layer
Uses IP address
Handles routing across networks
🔗 Network Access Layer
Handles MAC addressing + physical transmission
Application → Transport → Internet → Network Access
| OSI Model | TCP/IP Model |
|---|---|
| 7 Layers | 4 Layers |
| Theoretical | Practical |
| Developed by ISO | Developed by DARPA |
| More detailed | Simplified & real-world |
| OSI | TCP/IP |
|---|---|
| Application | Application |
| Presentation | Application |
| Session | Application |
| Transport | Transport |
| Network | Internet |
| Data Link | Network Access |
| Physical | Network Access |
👉 OSI model is a 7-layer theoretical framework for understanding network communication, while TCP/IP is a 4-layer practical model used in real-world Internet communication.
