The Constitution of the United States is the document that sets out the country’s fundamental law. It specifies how the government is to be set up and it also provides a list of things that the government can and cannot do. It does so in seven main sections that are called “articles.” Since the ratification of the Constitution, there have also been 27 amendments that have changed various provisions of the Constitution or which have added to it.
The first three articles of the Constitution set up the three branches of the national government. Article I sets up the legislative branch, Article II the executive branch, and Article III the judicial branch. These articles set out things like the qualifications for office, how the officials are to be selected, and what powers each branch has.
The fourth article sets out the relationships between the states. It says, for example, that all of the states have to send fugitives from justice back to the states from which they fled. It also sets out a few obligations that the federal government has to the states, such as ensuring that they all have republican forms of government.
The fifth article is very short. It simply tells how the Constitution can be amended. It sets out the process by which both the federal government and the states have a role in the process.
Article VI is also very short. It is mainly important because it establishes that the Constitution and the laws made by the federal government are the supreme law of the land. It also forbids religious tests for office.
The last article simply says how the Constitution is to be ratified. It is one sentence long and no longer of anything other than historical interest.