There is the element of compulsion which enters into the relationship between the citizen and the state. In a modern state all members are its citizens. Gone are the days, when according to Aristotle, only those who had the power to take part in the deliberative or judicial administration were said to be the citizens of the state.
Modern states are large territorial states with huge population and the citizens are under no obligation to take part in the deliberative or judicial administration of the state.
In a modern state, a citizen is its member enjoying full civil or political rights. No section of the population is excluded from citizenship.
Generally, no discrimination is made between one member and another in a state on the ground of religion, class, caste, creed, region, language, race, sex or profession.
A good example is India. Certain states, however, place restrictions on particular sections of population and deny certain rights given to other citizens.
The citizens must be absolutely loyal to the state and must serve the state wholeheartedly.