Is like what Sean Roberts said: That the government is made up of three branches, which are made to see each other to make sure no branch is dominating the other two. They are all the time trying to find a balance among the three branches (Judicial, Executive, and Legislative). The founders created this in order to have an effective government in decision making.
Also, Gridlock is when something isn't moving. You can also call it a stalemate. The government is meant to have gridlock. For example, it can take a WHILE, a few years, for a decision to be made on a certain issue, and when it has to do with something controversial it takes longer (like abortion, which still, to this day, is a heated topic in politics), which makes people complain about how "slow" the American government is when making decisions.
Hope this helps.