What does the word expressed power means in american government

In the American government, the legislative branch, Judaical branch, and the executive branch all part of the american government. The Congress, however, has the most clearly expressed power. When the founding fathers were writing the consitution they made sure that there were clearly expressed powers, and that one person didn't have to much. What this means is that the powers each branch were given, were clearly stated, and listed, so that each branch didn't have to much power. Hope that helps and if not got to http://study.com/academy/lesson/expressed-powers-definition-examples.html