I have put blanks in your question because it seemed like this must be a fill in the blanks question.
This question is asking you to understand the nature of America's government, which has a system of separation of powers. The Framers of the Constitution did not want any one part of the government to have too much power, so they split the powers up among the three branches.
The Congress (legislative branch) has the power to make laws. But Congress cannot actually go out and force anyone to comply with the laws they make. That is the job of the president, or the executive branch. So the president has the power to enforce the laws. If people disagree on what the laws mean, someone has to decide. That is the role of the judicial branch. It has the power to interpret laws, saying what they actually mean.