What are the seven layers of the OSI model?

The main objective of the OSI model is to process the communication between two endpoints in a network.

The seven open systems interconnection layers are listed below:

  • Application layer (layer 7) - It allows users to communicate with network/application whenever required to perform network-related operations.
  • Presentation layer (layer 6) - It manages encryption and decryption of data required for the application layer. It translates or formats data for the application layer based on the syntax of the application that accepts.
  • Session layer (layer 5) - It determines the period of a system that waits for other applications to respond.
  • Transport layer (layer 4) - It is used for sending data across a network and also offers error checking practices and data flow controls.
  • Network layer (layer 3) - It is used to transfer data to and fro through another network.
  • Data-link layer (layer 2) - It handles the flow of data to and fro in a network. It also controls problems that occur due to bit transmission errors.
  • Physical layer (layer 1) - It transfers the computer bits from one device to another through the network. It also controls how physical connections are set up to the network and also bits represented into signals while transmitting either optically, electrically, or radio waves.

This is the blueprint for host to host communication . So this is basically to understand the flow of communication which starts as follows

  1. Application layer

Things like email, web page are at this layer

  1. Presentation layer

Here data at application represented in particular format.

S3. ession layer

Data’s are sent as part of each session to the recipient

  1. Transport layer.

Ensure the communication from sender to receiver via TCP/UDP.

  1. Network layer

This is where ip routing happens finding remote host location and forward packets

  1. Datalink layer

Here same communication happens in terms of frames and forwarding to the host with in LAN

  1. Physical layer.

Here is the 1s and 0s seen in terms of bits.