We know that some powers belong entirely to the federal government (enumerated powers) and others are entirely the states' (reserved powers). however, since the responsibilities of states and the federal government do overlap quite a bit on occasion, the founding fathers also saw the need for some power-sharing. that's why there are so-called powers, such as the power to tax, the power to maintain courts (i. e. state and federal courts, as you now know), and the power to borrow money.