Layers of the OSI stack Seven Layers of the OSI Stack Layer Short Description 7. Application Provides services that directly support user applications.
Presentation Translates data formats and adds encryption.
Session Sets up and tears down connections, or sessions. Transport Adds identifiers to processes and deals with error-handling information. Network Handles internetwork sequencing, addressing, and routing. Data Link Adds error-checking information and organizes bits info frames. Physical Transmits and receives bits over the physical media.