Application Layer

In Network Architecture, the application layer is the 7th and final layer and is where all protocols and methods that are process-to-process communications are contained. These process communications move across an IP network and the application layer uses cues from the transport layer protocol to establish these host-to-host connections. Application functionality occurs above the transport layer, but critical actions are also performed in both the session and the presentation layers. The Open Systems Interconnection model is responsible for establishing strict modular separation (and differences in functionality) at all of these layers and provides protocol implementation for each as well.