The government shutdown happened. Here's what it means.

Vast parts of the U.S. government shut down at midnight Friday after the Senate failed to pass a spending bill that included $5.7 billion to fund one of President Donald Trump's biggest priorities: a physical border wall on the border with Mexico. The shutdown will affect hundreds of thousands of government workers, many of whom will be asked to work without pay until a deal is reached.

The Senate adjourned at 8:30 p.m. Friday with no deal in sight, so as funding ran out at midnight, a partial government shutdown began, affecting nine federal agencies including the Departments of Agriculture, Commerce, Homeland Security, Housing and Urban Development, Interior, Justice, State, Transportation and Treasury.

President Trump backed a bill he knew even the Republican-controlled Senate would not pass, and yet on Twitter, he blamed the Democrats: “There’s nothing we can do about that because we need the Democrats to give us their votes.”

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The Senate is scheduled to resume negotiations on Saturday, but until they reach a deal, it's another government shutdown, the third of the year when Republicans have had complete control of the levers of government.

Here’s how it breaks down:

800,000 federal employees will either temporarily work without pay or be placed on leave.

About 420,000 federal workers are considered "essential" and will be expected to work without pay and 380,000 federal workers are being sent home, according to data compiled by Senate Democrats.

People who have jobs in public safety functions will have to report to work without pay, and will receive delayed salaries. That includes some employees in the Homeland Security Department, Transportation Department and Justice Department. This means that border control agents, TSA agents, air traffic controllers, federal law enforcement and prison employees will remain on duty without pay during the holidays. These workers should be able to collect the pay they’re owed after the shutdown is over.

Federal employees placed on leave without pay include Department of Commerce and NASA staff, Forest and National Park Services, IRS, Housing and Urban Development workers, and some Transportation Department employees, according to the Senate Dems data report.

9 federal departments will close, and some non-governmental agencies will be affected.

The federal departments that will close their doors include Treasury, Agriculture, Homeland Security, Transportation, Commerce, Justice, Housing and Urban Development, State and Interior. This means that while people with more crucial roles will remain on the job without pay, the departments will not fully function.

Non-federal employees will feel the impact of the shutdown too. “Dozens” of non-governmental agencies like less-trafficked national parks may be closed, and the National Zoo in Washington will close, but the animals will still be fed and cared for. The Smithsonian Museums will be affected since both programs get their funding from the Department of Interior, according to the data report.

While federal workers have been compensated for their unpaid work and time off after previous shutdowns, it’s not guaranteed.

What about average people in the U.S.?

During the shutdown, Americans will still wait in airport security lines, have access to medical care, and be able to send last-minute holiday gifts via the mail.

Programs that fall in the category of “mandatory spending” will function, including Social Security, Medicare, and Medicaid, and the U.S. Postal Service will continue to function.

Food stamps will still be accessible, since the Department of Agriculture has a limited amount of funding to maintain the program if a new budget hasn’t been approved. And, if you’re traveling to a national park for the holidays, you might want to double-check that it’s still open, since during the government shutdown in January, one-third of national parks were closed.

Cover: The U.S. Capitol is seen reflected after rain in Washington, Friday, Dec. 21, 2018. The Republican-led House approved funding for President Donald Trump's border wall in legislation that pushes the government closer to a partial government shutdown. The bill now goes to the Senate. (AP Photo/Jose Luis Magana)