Article I describes the Congress, the legislative branch of the federal government. Section 1, reads, "All legislative powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives." The article establishes the manner of election and the qualifications of members of each body. Representatives must be at least 25 years old, be a citizen of the United States for seven years, and live in the state they represent. Senators must be at least 30 years old, be a citizen for nine years, and live in the state they represent.

Article I, Section 8 enumerates the powers delegated to the legislature. Financially, Congress has the power to tax, borrow, pay debt and provide for the common defense and the general welfare; to regulate commerce, bankruptcies, and coin money. To regulate internal affairs, it has the power to regulate and govern military forces and militias, suppress insurrections and repel invasions. It is to provide for naturalization, standards of weights and measures, post offices and roads, and patents; to directly govern the federal district and cessions of land by the states for forts and arsenals. Internationally, Congress has the power to define and punish piracies and offenses against the Law of Nations, to declare war and make rules of war. The final Necessary and Proper Clause, also known as the Elastic Clause, expressly confers incidental powers upon Congress without the Articles' requirement for express delegation for each and every power. Article I, Section 9 lists eight specific limits on congressional power.
Without quoting directly from the text give me a summary of Article 1 of the U.S. Constitution.
Article 1 of the U.S. Constitution defines the legislative branch of our government, or Congress, and establishes the qualifications to serve as part of that body.  It goes on to define the powers and responsibilities delegated to Congress in providing for the defense and general welfare of the United States.