Regarding legislative relations, there is a threefold division of powers in the Constitution.
We have followed a system in which there are two lists of legislative powers, one for the Centre and the other for the State, known as the Union List and the State List, respectively.
An additional list called the Concurrent List has also been added.
The Union List which consists of 97 subjects of national interest is the largest of the three lists.
Some of the important subjects included in this list are: Defence, Railways, Post and Telegraph, Income Tax, Custom Duties, etc.
The Parliament has the exclusive power to enact laws on the subjects included in the Union List for the entire country.
The State List consists of 66 subjects of local interest. Some of the important subjects included in this List are Trade and Commerce within the State, Police, Fisheries, Forests, Industries, etc.
The State Legislatures have been empowered to make laws on the subjects included in the State List.
The Concurrent List consists of 47 subjects of common interest to both the Union and the States.
Some of the subjects included in this list are: Stamp Duties, Drugs and Poison, Electricity, Newspapers etc.
Both the Parliament and the State Legislatures can make laws on the subjects included in this list.
But in case of a conflict between the Union and the State law relating to the same subject, the Union law prevails over the State law.
Power to legislate on all subjects not included in any of the three lists vests with the Parliament.
Under certain circumstances, the Parliament can legislate on the subjects mentioned in the State List.