The seventh layer of the OSI Open Systems Interconnection Model performs an application function and is closer to the end users. Through this layer, users interact with the other layers of the entire OSI model. It hosts the network services that provide the functionality and interactions of applications on networks.
This is the most accessible layer to end users, as this is where they interact with applications and services on the network.
What tasks are performed at the application layer:
- providing access to network services and resources: websites, email, file servers, databases;
- data exchange between different applications using standardized protocols: HTTP, SMTP, HTTPS, FTP;
- providing an interface for user interaction with applications: graphical interfaces, command lines, web interfaces;
- managing the creation and termination of communication sessions between applications: browser sessions, authentication;
- performing data and protocol conversions for interoperability;
- increased security through the use of authentication and encryption to protect information.