Main purpose of each article
Article II
Executive Branch
Article III
Judicial Branch
Article I
Legislative Branch
Article VI
The Article guarantees that the United States under the Constitution would assume all debts and contracts entered into by the United States under the Articles of Confederation, sets the Constitution and all laws and treaties of the United States to be the supreme law of the country, and finally, it requires all officers of the United States and of the states to swear an oath of allegiance to the United States and the Constitution when taking office.
Article V
deals with the procedures to amend the Constitution.
Article IV
defines the relationship between the states and the federal government and the rights of citizens of the states.
Article VII
describes the method of ratification of the Constitution.