The acronym OSI stands for the Open Systems Interconnection model, which is a conceptual framework used to understand and implement networking protocols in seven layers. These layers include: Physical, Data Link, Network, Transport, Session, Presentation, and Application. Each layer serves a specific function, enabling diverse communication systems to interoperate. Understanding the OSI model helps network professionals diagnose problems, design networks, and ensure effective data transfer across various platforms and devices. It remains a foundational concept in networking education and practice.