OSI (Open Systems Interconnection)

 

The seven layers are:

1.      Layer 7: The application layer

2.      Layer 6: The presentation layer

3.      Layer 5: The session layer

4.      Layer 4: The transport layer

5.      Layer 3: The network layer

6.      Layer 2: The data-link layer

7.      Layer 1: The physical layer

Application	-File, printing, message, database, and application services.
Presentation	-Data encryption / decryption, compression, and translating services.
Session	-Dialog control.
Transport	-End to end connection.
Network	-Routing.
Data Link	-Framing.
Physical	-Physical topology.