Checks and balances means that we have set up three branches of government the Executive, Legislative and Judicial. The purpose of the three branches was to divide the powers of government. There was an attempt to make each branch has about the same powers as each other branch. That is what is meant by balance. In order to see that they remained equal we set up a system oof checks, The checks were methods were each branch could watch and override the powers of the other two, For example, the President can veto or forbid a bill passes by Congress from becoming a law, but Congress could by a 2/3 vote override the presidential veto. There are many other checks that you will learn about in school.