A government shutdown is nearing this weekend. What does it mean, who's hit and what's next?

A U.S. government shutdown would disrupt many services that Americans rely on and squeeze federal workers. Social Security checks would still go out, but other government functions would be severely curtailed if the shutdown comes Sunday. Federal agencies would cease all actions deemed nonessential, and many of the federal government's roughly 2 million employees, as well as 2 million active-duty military troops and reservists, wouldn't be paid. People applying for government services such as clinical medical trials, firearm permits and passports could see delays. Head Start programs serving more than 10,000 disadvantaged children would immediately lose federal funding. National parks would close on Monday.