Can you explain the OSI model and its main layers?

The OSI (Open Systems Interconnection) model is a conceptual model that describes how data is transmitted in networks through seven layers:

1. Physical Layer — transmission of bits over physical channels (cables, radio waves).
2. Data Link Layer — organization of frame transmission, error control, and media access.
3. Network Layer — routing of packets between network nodes.
4. Transport Layer — ensuring reliable data transfer, flow control, and error control (e.g., TCP).
5. Session Layer — management of sessions and connections between applications.
6. Presentation Layer — data transformation, encoding, encryption.
7. Application Layer — interface for applications, providing network services (HTTP, FTP, SMTP).

This model helps standardize the interaction of network devices and protocols.