The most clearly delegated governmental powers, those actually written into the constitution, are the:

"Expressed powers" or "enumerated powers."

Strict constructionists and loose constructionists differ over whether the government's powers should be limited to those specifically enumerated powers.  Strict constructionists read the Constitution as giving the federal government only those specifically delegated powers.  Loose constructionists argue that anything not specifically forbidden by the constitution can be within the window of what the government needs to do in adapting to the needs of time and circumstances.