What was the difference between the Articles of Confederation and the Constitution?

The Articles of Confederation created a weak central government. The Constitution created a strong central government. The Articles did not create an executive branch. Congress was a unicameral legislature. There was no federal court system under the Articles. Congress could not enforce the laws nor levy and collect taxes without the approval of the states, under the Articles. A major weakness under the Articles was its lack of power to regulate trade between the states and with foreign nations.