Question

why and how is power shared in democracy

Answer 1

The first reason is Power sharinghelps to reduce the possibility of conflict between social groups. Power sharingis a good way to ensure the stability of political order as social conflict often leads to violence and political instability. ... The second reason is the very spirit of democracyis power sharing.

Answer 2

In the Indian Federalism, the powers between the Union and the States have been divided by the three lists of power.

Union List- The Union list contains matters of national concern like foreign affairs, railways, currency etc. The Union government has teh sole right to make laws on the subjects stated in this list.

State List- Some matters of regional interest like education, health, agriculture etc, have been placed under the State list and the State has the sole right to make laws on these subjects.

Concurrent List:- Matters of common interest like economic and social planning has been placed in the concurrent list. Both the states and teh Union  has teh authority to make laws on these subjects.

But Indian federalism that is quasi-federal in nature gives more authority to the centre in the sense that if there is any cash between the Union and the State regarding the matters of the concurrent list then the decision of the Union shall prevail.