In a federal system,the essence of specifying the constitutional relationship between the center and the constituent units is to

It was Sir Oliver Lyttleton Constitution 1954 that classified governmental powers into three-the Exclusive, the Concurrent and Residual Powers.

Exclusive Powers-matters where only the federal government can legislate.

Concurrent List-matters where both the federal governments governments can legislate.

Regional Powers-matters where only the Regional or State government legislate. Coming back to the Concurrent List, it should be noted that the federal government takes precedence in case of any conflict.