• 2 yr. term
• must be a 7 yr U.S. citizen
• must live in district/state representing.
• must be 25 yrs. Old
• contains 435 members
• led by Speaker of House
• elected by the people of the state Powers
• Majority elects Speaker and officers
• Has the sole power to impeach
• Debate usually limited to one hour
• Referral of bills hard to challenge
• Power to begin tax bill
• Breaks tie in Electoral College
Structure
• 6 yr term
• must be a 9 yr U.S. citizen
• must live in state representing
• must be 30 yrs old
• contains 100 members
• led by Vice-President (Cheney) Powers
• Senators have one vote each
• Senate chooses officers and a President pro tempore
• Has sole power to try impeachments
• Referral of bills easily challenged
• Rules Committee weak
Short answer: There are wide swaths of the federal government that need to be funded each year in order to operate. If Congress can't agree on how to fund them, they have to close down. And, right now, Congress can't agree on how to fund them.
To get a bit more specific: Each year, the House and Senate are supposed to agree on 12 appropriations bills to fund the federal agencies and set spending priorities. Congress has become really bad at passing these bills, so in recent years they've resorted to stopgap budgets to keep the government funded (known as "continuing resolutions"). The last stopgap passed on March 28, 2013, and ends on Sept. 30.
In theory, Congress could pass another stopgap before Tuesday. But the Democratic-controlled Senate and Republican-controlled House are at odds over what that stopgap should look like. The House passed a funding bill over the weekend that delayed Obamacare for one year and repealed a tax on medical devices. The Senate rejected that measure. They voted a few more times and still no agreement. So... we're getting a shutdown.
Does a shutdown mean everyone who works for the federal government has to go home?
Not