Congress has a variety of powers, but the three main powers are making laws, declaring war and amending the Constitution. These powers fall under both Houses of Congress.
Article I, Section 8 of the Constitution allows Congress to create laws. A congressperson or senator can introduce a bill, and it is sent to a committee to undergo legislative hearings. The committee may propose amendments before voting on the bill. If the bill is approved, it is sent back to the chamber where the entire House votes on it. The bill is then sent to the other chamber if it passes. Amending the Constitution is a harder process, and doing so requires a two-thirds majority from both chambers. The amendment must also pass in at least three-fourths of the state legislatures. Both chambers have the power to declare war, but only the Senate can ratify treaties with other governments.