It means split of society between rich and poor classes.
The rich enjoy all possible facility of life and lead a very good standard of life.
Whereas the poor people even do not meet the meals of two times in a day. They are unable to fulfil even their basic necessities.
Harm of Economic Inequality :
Economic inequality is harmful for the success of democracy as it intensify the ego among the rich people while inferiority complex among the poor, and emotional outburst are seen in strikes, murder, decoity and class conflicts.