The OSI (Open Systems Interconnection) model is a theoretical framework that describes the different layers involved in transmitting information over a network. It was developed by the International Organization for Standardization (ISO) in the late 1970s. The OSI model divides the process of transmitting information into seven separate layers, each with a specific function:
- Physical Layer: Deals with the electrical and physical aspects of transmitting data over a network, including cable and connector specifications.
- Data Link Layer: Handles the transfer of data between devices on a single network segment, including error detection and correction.
- Network Layer: Handles the routing of data between different network segments, including internetwork addressing.
- Transport Layer: Ensures reliable delivery of data between applications, including flow control and error checking.
- Session Layer: Controls the establishment, management, and termination of connections between applications.
- Presentation Layer: Deals with the formatting of data, including encryption and compression.
- Application Layer: Provides a user interface and allows applications to communicate with other systems.
The OSI model provides a common reference framework that helps understand the various protocols and technologies involved in networking.