Open Systems Interconnection Model (OSI Model)

The Open Systems Interconnection (OSI) Model is a conceptual and logical layout that defines network communication used by systems open to interconnection and communication with other systems. 

The model is broken into seven subcomponents, or layers, each of which represents a conceptual collection of services provided to the layers above and below it. The OSI Model also defines a logical network and effectively describes computer packet transfer by using different layer protocols.

The OSI Model may also be referred to as the seven-layer OSI Model or the seven-layer model.

Techopedia explains Open Systems Interconnection Model (OSI Model)

The OSI Model was developed by the International Organization for Standardization (ISO) in 1978. While working on a network framework, ISO decided to develop the seven-layer model. 

OSI’s seven layers are divided into two portions: hot layers and media layers. The hot portion includes the application, presentation, session and transport layers; the media portion includes the network, data link and physical layers.

The OSI Model works in a hierarchy, assigning tasks to all seven layers. Each layer is responsible for performing assigned tasks and transferring completed tasks to the next layer for further processing. Today, many protocols are developed based on the OSI Model working mechanism.