The OSI model, known as Open Systems Interconnection, represents a theoretical framework for data communication, developed by the ISO (International Organization for Standardization). It structures data transmission into seven distinct layers, each with its own responsibilities and tasks.

From the highest layer to the lowest, the OSI model includes the Application layer, which provides interfaces for user applications, such as email, file sharing, and web browsing. Next, the Presentation layer is responsible for converting and managing data so that it can be interpreted by applications, ensuring format translation, compression, and encryption.

The Session layer establishes, manages, and terminates communication sessions between applications on remote machines, in addition to ensuring synchronization and control of the dialogue. As for the Transport layer, it guarantees the reliable and orderly distribution of data between hosts by managing connections, data segmentation and reassembly, with error correction mechanisms.

At the Network layer, data packet routing across the network is ensured, determining the optimal data transfer path, managing IP addresses, and switching packets. The Data Link layer focuses on managing transmission errors, collision detection, and access to shared media, fragmenting data into frames and managing access control.

Finally, the Physical layer handles the hardware aspects of data transmission, such as cables, electrical signals, and modems, defining the physical and electrical specifications of network equipment.