Article 5 describes how the US Constitution can be changed or updated. We see this in the form of ammendments.
Article 4 describes the establishment of states and their relationship to each other. It also describes the interaction with the central federal government.
Article 3 focuses on the judicial branch and the powers of the court. They are there to establish law and order.
Article 2 establishes the executive branch of the federal government. It also describes their roles and responsibilities.