A social contract is an agreement between the people of a state and the government of a state. The people agree to follow certain rules made by the government. These rules are usually called laws. Laws help to make sure people have rights and that their rights are taken care of. One kind of social contract is a constitution. A constitution sets limits on the powers of government leaders, police, and other people who have authority.
The first social contracts were written by philosophers such as John Locke and Jean-Jacques Rousseau. They saw good government as coming from social contracts. Rousseau wrote a book called The Social Contract. Both the United States Declaration of Independence and United States Constitution are social contracts.