The document describes the 7 layers of the OSI model from physical to application. The layers are physical, data link, network, transport, session, presentation, and application which is the top layer where users interact with software applications.

1. Modelo OSI

2. 1 Physical

3. 2 Data Link

4. 3 Network

5. 4 Transport

6. 5 Session

7. 6 Presentation
HI
HELLO

8. 7 Application
CHAT