# OSI Model

- [Intro](/focus2learn/osi-model/intro.md): OSI stands for Open Systems Interconnection. It has been developed by ISO – ‘International Organization of Standardization‘, in the year 1984.
- [OSI Model Layers - Functions and Protocols](/focus2learn/osi-model/osi-model-layers-functions-and-protocols.md): OSI model stands for Open System Interconnection model. OSI model is a reference model and used for communicating with systems that are open for communication with other systems.
- [TCP/IP Protocol Suite](/focus2learn/osi-model/tcp-ip-protocol-suite.md)
- [Layers Functionalities](/focus2learn/osi-model/computer-networks.md)
- [TCP and UDP ports](/focus2learn/osi-model/tcp-and-udp-ports.md)
- [Network Connecting Devices](/focus2learn/osi-model/networking-devices.md)
- [Network Security Devices](/focus2learn/osi-model/network-security-devices.md)
- [Network Vulnerability](/focus2learn/osi-model/network-vulnerability.md)
- [Kerbros](/focus2learn/osi-model/kerbros.md): Kerberos is an Authentication Protocol for client/server applications. This protocol relies on a combination of private key encryption and access tickets to safely verify user identities.