TCP/IP vs OSI model are rules that were set to ensure all devices within the some or different network communicate. These two set of model are used widely in day to day activities like watching a movie, gaming, even sending Whats app messages
Don’t worry they sound technical, but we’ll keep it super simple. Think of them like maps that explain how data (your text, video, or picture) moves from one device to another.
Key Takeaways
OSI = 7 layers (theory), TCP/IP = 4/5 layers (practice).
OSI is detailed and great for learning. TCP/IP is what runs the internet.
Think of it like: OSI is the classroom map, TCP/IP is the real highway system.
Both models are useful—OSI for learning and troubleshooting, TCP/IP for real-world networking.
What is the OSI Model?
The OSI Model (Open Systems Interconnection Model) is a seven layer model that explains how data moves from one device to another in a network. Each layer has a specific role, starting from the Physical layer (cables, Wi-Fi signals) up to the Application layer (apps like WhatsApp or browsers).
Think of it like a step-by-step delivery system: one layer prepares the data, the next adds addressing, another ensures reliability, and so on, until your message or file reaches its destination. The OSI model isn’t what the internet actually uses—it’s more of a teaching tool that helps beginners and professionals understand, design, and troubleshoot networks in a structured way.
The OSI model has seven layers. Each layer has a specific job.
Physical – the actual wires, Wi-Fi, or cables.
Data Link – local delivery using device IDs (MAC addresses).
Network – moves data across different networks using IP addresses.
Transport – makes sure data arrives correctly (TCP or UDP).
Session – manages the “conversation” between two devices.
Presentation – translates data into a format apps can use (encryption, compression).
Application – the apps you see, like your browser or email.
What is the TCP/IP Model?
The TCP/IP model is the real set of rules the internet uses every day. It has fewer layers (4 or 5, depending on how you look at it).
- Application – covers OSI’s Application, Presentation, and Session.
- Transport – same as OSI’s Transport.
- Internet (Network) – same as OSI’s Network.
- Network Access (Link + Physical) – combines OSI’s bottom two layers.
Think of TCP/IP as the actual highway system we drive on, while OSI is more like a classroom map that explains how highways should work.
ALSO READ: What is an IP Address? A Beginner’s Guide to IPv4 & IPv6
| OSI Model | TCP/IP Model |
|---|---|
| 7 layers | 4–5 layers |
| Used for learning and teaching | Used in the real world (internet) |
| More detailed | More practical |
| Created later (1980s) | Came first (1970s, ARPANET) |
Common Questions Beginners Ask
Q: Is TCP/IP the same as OSI?
No. OSI is a learning tool with 7 layers, TCP/IP is the real-world system with 4 or 5 layers.
Q: Which one is used in real life?
The internet uses TCP/IP. But OSI is still taught because it helps people understand and troubleshoot networks.
Q: Why does OSI have more layers?
It breaks things into smaller, more detailed parts. This makes it easier to study. TCP/IP groups some of them together.
Q: Which layer does a router work at?
Routers work at the Network layer (they move data between networks using IP addresses).
Both the OSI Model and the TCP/IP Model play a big role in understanding how computer networks work. The OSI Model is more of a teaching and reference tool, breaking networking into seven clear layers to explain how data travels. On the other hand, the TCP/IP Model is simpler with four layers and is the one actually used in real-world networking, especially on the internet.
In short:
-
OSI = theory and learning
-
TCP/IP = practice and implementation
Knowing the difference between the two helps beginners build a strong foundation in networking. Once you understand these models, it becomes much easier to grasp how devices talk to each other, how data flows across the internet, and how network engineers troubleshoot problems.
Q: What’s the difference between TCP and UDP?
- TCP is reliable, like sending a registered letter that must be signed.
- UDP is faster but less reliable, like shouting across a room—you hope they hear you, but there’s no guarantee.