How The Internet Works

Understanding the OSI Model - The 7 Layers of Networking

What is the OSI Model?

The Open Systems Interconnection (OSI) model is a conceptual framework that describes how data travels across a network. It divides network communication into 7 distinct layers, each with specific functions.

When you send a message, it travels down through all 7 layers on your device, across the network, and back up through all 7 layers on the receiving device.

The 7 Layers at a Glance

Easy Way to Remember

From Layer 7 to Layer 1:

"All People Seem To Need Data Processing"

Application → Presentation → Session → Transport → Network → Data Link → Physical