Montesquieu, a French philosopher of the 18th century, is often credited with the theory of separation of powers. According to Montesquieu's theory, "the powers of government should be divided into three separate branches-

1.The legislative, 

2.The executive, and

3.The judiciary.

 Each branch should have a distinct function, and each should be independent of the others, with no one branch having too much power or control.

In Montesquieu's Theory-

I.The Legislative Branch is responsible for making laws,

II.The Executive Branch is responsible for enforcing laws and

III.The Judiciary Branch is responsible for interpreting laws and resolving disputes.

Each branch should be able to check and balance the others to ensure that no one branch becomes too powerful.