Within social system there are various subsystems like political system, economic system, religious system, educational system etc. David Easton and Gabriel Almond played a leading role in developing the system theory in the field of political science. According to Easton a political system is that system of interactions in any society through which binding or authoritive allocations are made and implemented. Thus it is making of binding or authoritive an allocation that distinguishes the political system from other systems both within and outside the overall society.
Max Weber has defined political system as a human community that successfully claims the monopoly of legitimate use of physical force within a given territory. Almond defines political system as that system of interactions to be found in all independent societies that perform the functions of integration and adaptation by means of the employment or threat of employment of more or less legitimate physical compulsion. As a student of sociology it may be noted that force or physical coercion forms an essential element of a political system. Althoughother systems like churches or families or business firms employ authority of one kind or the other but what distinguishes political systems from other types of social sub-system is that the latter do not have the absolute coercive powers over the lives of the individuals. It is the monopoly of coercive power that characterizes the relationships between the political system and non-political systems. Since state is the most powerful political organization which regulates the social relationship of man and is the overall control institution of society therefore its study becomes important for a student of sociology.