Layers in OSI Model
The OSI (Open Systems Interconnection) model is divided into seven processes called layers. Each layer in the OSI model is responsible for specific functions that help in the transfer of data from one node to another in a network. These layers work together to ensure that communication between devices is seamless and efficient.

Functions of Each Layer
- Physical Layer: This layer deals with the physical connection between devices. It defines the hardware specifications, such as cables, switches, and network interface cards.
- Data Link Layer: The data link layer is responsible for the reliable transmission of data across a physical link. It also handles error detection and correction.
- Network Layer: This layer is concerned with routing packets from the source to the destination. It determines the best path for data to travel through the network.
- Transport Layer: The transport layer ensures that data is delivered reliably and in the correct order. It also handles flow control and error recovery.
- Session Layer: This layer establishes, maintains, and terminates communication sessions between devices.
- Presentation Layer: The presentation layer is responsible for data translation, encryption, and compression.
- Application Layer: The application layer provides an interface for applications to access network services. It includes protocols such as HTTP, FTP, and SMTP.

Conclusion
The division of the OSI model into seven layers helps in simplifying the complex process of network communication. Each layer has a specific role to play, and they work together to ensure that data is transmitted efficiently and securely across networks.