• Updated at 10:42: The Supreme Court will allow part of the travel ban to take effect; some immigrants will be banned from entering the country. 
  • Update at 10:29 a.m. ET: The  Supreme Court has ruled that it will hear arguments over President Donald Trump's second executive order banning travel to the United States.

Original story:

The Supreme Court will rule on Monday whether to hear the challenge to President Donald Trump’s executive order banning immigration from several predominately Muslim nations.

That executive order and the revised order that followed were both challenged in lower courts, which ruled in favor of the states that brought suit, setting up today’s decision by the U.S. Supreme Court.

Here’s what can happen Monday and some background on the executive order.

What is the ban?

The original ban was issued on January 27, 2017, and it did the following:

- Suspended the U.S. Refugee Admissions Program for 120 days

- Cut the number of refugees to 50,000 in 2017

- Banned Syrian refugees from entry into the United States indefinitely

- Barred immigrants from seven predominantly Muslim countries -- Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen -- from entering the United States for 90 days.

How was it revised?

The revised order, executive order 13780, removed Iraq from the list of nations included in the ban, allowed refugees already approved by the State Department to enter the U.S. and lifted the ban on Syrian refugees. It was to go into effect at midnight on March 16, 2017.

What will happen on Monday?

The court will do one of three things Monday. It will either uphold Trump’s ban, refuse to hear the case or say it will hear the case in the fall when the court reconvenes.

What happens if the Supreme Court rules in Trump’s favor?

If the court rules in favor of the administration, the ban can be implemented within 72 hours.

What happens if the justices refuse to hear the case?

If the justices refuse to review the case, the lower court rulings will stand, stopping the Trump administration from banning entry into the U.S. based on the country from which a person emigrates.

Will the Supreme Court hear arguments?

Justices could choose to hear arguments about the ban in the fall. In the meantime, the lower court orders would stand.

What is the background?

President Trump signed an executive order that would ban refugees and immigrants from seven mostly Muslim countries from entering the United States for 90 days and would suspend a refugee program for 120 days. It would also ban Syrian refugees from entering the country.

That order sparked protests around the country and around the world. The states of Washington, Oregon, Minnesota, New York, Massachusetts and Hawaii filed suits over the ban.

In three days, from January 28 to January 31, 50 cases were filed against the order.

The courts granted a nationwide temporary restraining order that suspended much of the order. The 9th District Court of Appeals upheld the restraining orders.

A revised order was issued in March. That order, like the first, ran into legal challenges. A judge in Hawaii suspended the revised order, ruling that if the ban went into effect, it would likely cause "irreparable injury" by violating protections granted by the First Amendment against religious discrimination.

The judge said tweets by Trump suggested that the order sought to ban people on the basis of their religion, and not in the interest of national security, as Trump had claimed.