OSI (Open System Inteconnect) model is a generic model which is provide guidance to develop any network model. When OSI Model was released TCP/IP already implemented and used by companies so OSI is not get enough attention. After being lunched, the OSI model did not meet the practical needs as well as TCP/IP model. OSI Model is currently theoretical model.
OSI model is a layered model and has 7 layers. Changes in one layer do not affect other layers