Definition
The OSI model is a conceptual framework that facilitates communication between different systems using standard protocols. It is the universal language for computing networking and divides the communication system into seven layers.
OSI Models Layers
- Physical layer: This layer facilitates the cable or wireless connection between network nodes to transmit raw data.
- Data link layer: This layer initiates and terminates a connection between two physically connected nodes.
- Network layer: This layer breaks down segments into packets and reassembles the packets at the receiving end. It also identifies the best path for the data packets.
- Transport layer: This layer divides data into segments for transmission and reassembles them on the receiving end. It sends out data at a rate that the receiving device can manage and checks if it was received properly.
- Session layer: This layer creates sessions between devices, opens them, and closes them when the communication ends.
- Presentation layer: This layer defines how devices encrypt, compress, and encode data.
- Application layer: This is where end-user software (such as a browser or email client) uses application-layer protocols to send and receive data.