The OSI is an abstract model of how web link protocols and equipment should communicate and work together.

The OSI model is a technology standard maintained by theInternational Organization for Standardization (ISO).

Layers in the OSI model are ordered from the lowest layer to highest.

Chart of the OSI Model

Gorivero / CC-BY-SA-3.0 / Wikimedia Commons

Together, these layers comprise the OSI stack.

Generally speaking, software in these layers perform app-specific functions like data formatting,encryption, and connection management.

See these commonquestions and answers about the OSI modelfor more information.