The Open Systems Interconnection (OSI) is a theoretical model for network communication that is more abstract version of the TCP IP Model.
OSI Layers
Each layer transforms data from highest level into electrical signals at physical level. Receiving data is received at the lowest level and works up to the application layer for the user.
- Physical: Converts packets into electrical signals
- Data Link: Encodes and decodes packets into bits, adds MAC Addresses
- Network: Routes packet over network, adds IP addresses
- Transport: Create end-to-end connection, adds TCP Protocol or UDP Protocol header
- Session: Managing connections
- Presentation: Formats data for recipient, encrypts data, XML, JSON, binary…
- Application: The application, HTTP Protocol, FTP Protocol