Ans: Coupling means the interconnection of different modules with each other or we can say, it tells about the interrelationship of different modules of a system. A system with high coupling means there are strong interconnections between its modules. If two modules are involved in high coupling, it means their interdependence will be very high. Any changes applied to one module will affect the functionality of the other module. Greater the degree of change, greater will be its effect on the other. As the dependence is higher, such change will affect modules in a negative manner and in-turn, the maintainability of the project is reduced. This will further reduce the reusability factor of individual modules and hence lead to unsophisticated software. So, it is always desirable to have inter-connection & interdependence between modules.