A constitution writes down the most important principles, or rules, that are used to govern a country. All other laws made in Parliament and used in the courts have to follow the Constitution. They cannot contradict or go against the Constitution.
The government and even the President cannot do anything that goes against the Constitution. This is so because in our country the law courts (the judiciary) that make sure the constitution is followed are separate from the government. They must only follow the Constitution, not government.
Anyone (even an individual) or any organisation that notices a law or behaviour that goes against the Constitution can challenge that law or behaviour. They can force it to be changed or stopped.
The Constitution describes how a government must be formed, how it must be elected and how that government must run. It says that the government must listen to and work to help the people of the country.
The Constitution says what the government’s powers are, and what the government cannot have power over. It says that every person in South Africa has rights. These rights are written into the Constitution.