OSI (The Open Systems Interconnection model)

A networking model introduced by the International Organization for
Standardization (ISO) to promote multi-vendor interoperability.
The OSI model (The Open Systems Interconnection model) is a network model of a stack (store) of OSI/ISO network protocols. With this model, different network devices can communicate with each other. The model defines different levels of system interaction. Each level performs specific functions in this interaction.[Микитишин А., Митник П., Стухляв П., Пасічник В.]
The OSI model was developed in the late 1970s to support a variety of computer networking techniques that were then competing for use in the extensive national network interactions in France, Great Britain, and the United States. In the 1980s, it became the work product of the Open Systems Interoperability Group of the International Organization for Standardization (ISO). The model could not provide a complete description of the network and did not receive the support of architects at the dawn of the Internet, which was later reflected in the less-regulated TCP/IP, mainly under the leadership of the Internet Engineering Council (IETF).[Буров Є.]
A networking model introduced by the International Organization for
Standardization (ISO) to promote multi-vendor interoperability.

OSI is a seven-layered conceptual model consisting of the application, presentation, session, transport, network, data-link, and physical layers .

Sources:

Dictionary of Computer and Internet Terms (Vol. 1) John C. Rigdon, 2016 – 1471 c. – 872

Микитишин А., Митник П., Стухляв П., Пасічник В. (2013). Комп'ютерні мережі. Львів: ВЦ «Магнолія 2006». Буров Є. (2010). Комп'ютерні мережі: підручник. Львів: ВЦ «Магнолія 2006».