Once upon a time, there lived a family of 8 members in a small village. They were very poor and didn’t have enough money to make ends meet. Out of desperation, the head of the household decided to go to the city and look for a job. When he reached the city, he saw a big shopping mall. Most of the stores were connected with each other over a computer network so that customers can shop without leaving the mall. He was amazed by the setup and asked the IT manager how it works.
He was told that the network is based on the OSI model. The OSI model is divided into seven layers which work together in order to send data from one point to another. The seven layers are the application layer, the presentation layer, the session layer, the transport layer, the network layer, the data link layer, and the physical layer.
The application layer covers the different applications that are running on the network such as web browsers, emails etc. The presentation layer converts the data into a format compatible with the applications. The transport layer manages the reliable data transmission and the network layer handles routing of the data packets. The data link layer takes care of the physical addressing and error checking for the data packets. Lastly, the physical layer takes care of the actual transmission of the data packets over the physical medium.
The IT manager further explained to the man that these seven layers work together in a very efficient way to ensure that any data sent from one point to another reaches its destination safely and quickly.
The man thanked the IT manager for explaining the concept of the OSI model and went back to his village. He told his family and friends about the wonderful working of the OSI model and they all got fascinated by the concept.
