A January executive order by President Trump banning certain immigrants and refugees from entering the United States unleashed chaos at airports across the country, including Philadelphia. That order was revised in March in the face of legal challenges.

Whether you're just catching up on the news or looking for the latest info, here's a straightforward guide to what you might be wondering and what we know so far about the order's impact in Philadelphia.

So what was the original executive order, anyway?

Trump in late January signed an order that barred any refugee from being admitted to the United States for 120 days. Refugees from Syria were banned indefinitely. The order also suspended for three months admission for any citizen from seven primarily Muslim countries: Iraq, Iran, Syria, Yemen, Sudan, Libya, and Somalia. In a reversal, White House officials later said the order wouldn't apply to those with green cards, who are permanent legal residents of the country.

What's different about the new order?

On March 6, the president signed a scaled-back version of the order. The revised order eliminates Iraq from the list of banned countries, but still bars people traveling to the United States from Iran, Syria, Yemen, Sudan, Libya, and Somalia. The new order clarifies that current visa holders are not affected. It also no longer has langauge that would give priority to religious minorities.

What's the reaction to the new order in Philadelphia?

Many people in the Philadelphia area are still upset by the order, deriding it as a "Muslim Ban 2.0." Critics say it still targets people from Muslim-majority countries and will not make the country safer.

When will the new order be implemented?

It goes into effect March 16.

Are the orders legal?

Several legal challenges were filed in response to the original order, which was put on hold by a judge in Washington state. The White House has rescinded the old order but maintains that it was constitutional.

The new ban has also faced legal challenges; Philadelphia and other municipalities have filed amicus briefs supporting states that are arguing the ban is unconstitutional.

Lawyers for the seven immigrants who were sent away after landing in Philadelphia have sued the Trump administration, arguing that denying them entry to the United States violated the equal-protection guarantee of due process and the establishment clause of the First Amendment.

What happened to refugees and immigrants who tried to fly into Philadelphia under the old order?

Six Christian immigrants from Syria, all family members, who arrived at Philadelphia International Airport on a Qatar Airways flight the day after the order was enacted were sent back overseas. (The Assali family was later able to return to Pennsylvania, flying into New York City and then driving to Allentown, after courts blocked the order.)

An Iranian woman traveling alone with a valid visa was also sent back.

Four other migrants were detained for hours before being admitted into the country and released Sunday. Few details are known about those detained, but they included a man whose wife is a U.S. citizen, a man from an African nation, a man who is the spouse of a former translator for U.S. military forces in Iraq, and a woman.

An unknown number of people tried to board Philadelphia-bound planes overseas but were not permitted on the aircraft, or were turned away after arriving in Philadelphia and boarded other flights out of the country.

What about the protests at the airport?

Massive groups gathered at Philadelphia's airport the weekend after the initial order to protest the ban and the detainment of immigrants flying into the city. One day's crowd swelled to an estimated 4,000 to 6,000 protesters. Airports in other cities were also the sites of large demonstrations over the weekend. The protests in Philadelphia were peaceful, with no arrests.

The new ban, signed with less fanfare, was met with skepticism from critics but much less public demonstrations.

Did those protests affect flights in Philly?

An airport spokeswoman said takeoffs and landings were not affected. However, the throng of protesters spread to the arrivals road outside the baggage claim, forcing some vehicle traffic to be delayed or diverted.

What have local lawmakers said?

After the initial executive order was signed, many local Democratic politicians showed up at the protests or voiced their support for immigrants and refugees trying to enter the United States. Pennsylvania Gov. Tom Wolf, Philadelphia Mayor Jim Kenney, U.S. Sen. Bob Casey, U.S. Reps. Bob Brady and Dwight Evans of Pennsylvania, and Donald Norcross of New Jersey, and City Councilwoman Helen Gym were among those protesting at the airport.

Many Philadelphia-area Republicans have remained silent on the issue. However, two local Republicans – U.S. Reps. Brian Fitzpatrick and Charlie Dent – broke with Trump and spoke out against the initial ban. Sen. Pat Toomey of Pennsylvania said he supported the original order.

Some local Democratic legislators, including Casey and Sens. Cory Booker and Bob Menendez of New Jersey, have also spoken out against the new ban.

What was the controversy with the acting attorney general?

Acting Attorney General Sally Yates on Monday ordered Justice Department lawyers to stop defending the executive order. Trump then fired Yates and named Dana James Boente, U.S. Attorney for the Eastern District of Virginia, to serve in her place. He only remained in the position until Sen. Jeff Sessions, Trump's permanent pick for the post, was confirmed by the Senate.

Why is it notable that Penn's president spoke out against the ban?

Trump is a University of Pennsylvania alumnus, and the school's president, Amy Gutmann, has thus far been reluctant to overtly criticize him. But she issued a statement blasting the immigration order, her first detailed public criticism of Trump.

How are foreign students studying at Philadelphia-area schools affected?

The ban had the potential to pose big problems for students from the affected countries, who worried that they couldn't leave the United States if there was an emergency back home, have family members visit them at school or attend academic conferences overseas. While the ban does not apply to those holding valid visas, including student visas, higher education groups remain concerned about how the ban will affect academia.

Inquirer and Daily News opinion writers offer their takes:

Inquirer editorial: Trump's refugee ban is an insult to American values and ideals

Trudy Rubin: 'Extreme vetting' was occurring before Trump's order

Christine Flowers: Trump feeds xenophobic beast

Ronnie Polaneczky: Speaking with feet, hearts and voices

Will Bunch: Toomey flunks moral test, hides in Palm Springs with billionaire donors

John Baer: How are you enjoying President Trump thus far?

Signe Wilkinson: