What are the layers of the OSI model?

The layers of the OSI (Open Systems Interconnection) model are as follows:

1. Physical Layer: This layer deals with the physical transmission of data over the network, including the electrical, mechanical, and functional aspects of the network interface.

2. Data Link Layer: This layer is responsible for the reliable transmission of data between adjacent network nodes, ensuring error-free communication over the physical layer.

3. Network Layer: The network layer handles the routing of data packets across different networks, enabling communication between different networks and determining the best path for data transmission.

4. Transport Layer: This layer provides end-to-end communication between hosts, ensuring reliable and error-free data transfer. It also handles segmentation and reassembly of data packets.

5. Session Layer: The session layer establishes, manages, and terminates communication sessions between applications on different network devices. It also provides synchronization and checkpointing services.

6. Presentation Layer: This layer is responsible for the formatting, encryption, and compression of data to be transmitted over the network. It ensures that data is presented in a compatible format for the receiving application.

7. Application Layer: The application layer is the topmost layer and provides network services directly to the end-user applications. It includes protocols for various applications such as email, file transfer, and web browsing.