A wide array of people are affected by President Trump’s order, which bars for 90 days people from seven predominantly Muslim countries from entering the United States: Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen. It also bans all refugees for 120 days, and Syrian refugees indefinitely.

More than 100,000 visas for foreigners inside and outside the United States have also been revoked, at least temporarily, a government lawyer said in federal court on Friday.

After a review of the screening process, the order says officials may give recommendations for indefinite bans. Other countries may be added to the list as well.

There were more than 86,000 nonimmigrant, temporary visits by citizens from these countries in the 2015 fiscal year, including:

The ban affects people who are currently in the United States on temporary visas who would normally be allowed to travel to their home country and re-enter the United States, like students. According to the Institute of International Education, 17,354 international students from the seven countries were enrolled in American institutions during the 2015-16 school year.

The ban also affects people newly arriving on immigrant visas, which are issued based on employment or family status. People issued immigrant visas become legal permanent residents upon arrival in the United States and are issued a green card soon after.

In 2015, green cards were issued to 52,365 people from these seven countries. In general, about half of recent new legal permanent residents are new arrivals to the country, and the other half had their status adjusted after living in the United States.

The ban on all refugees to the United States is set at 120 days. Syrian refugees, who made up the second largest group of refugees to the United States in 2016, are barred indefinitely.

The order allows exceptions for refugees in minority religious groups and for those already in transit for whom a denial would cause undue hardship, or in line with pre-existing international agreements. The administration on Tuesday said that about 900 refugees would being processed this week for waivers because of hardship concerns. According to a State Department spokesperson, this group does not include individuals from Iran, Iraq, Libya, Somalia, Sudan, Syria or Yemen.

When the refugee program is reinstated, refugees in minority religious groups will be prioritized for acceptance. Although the order does not explicitly mention Christians as a minority religion that will be given preference, Mr. Trump said that was what he intended.

After initial confusion over whether Mr. Trump’s order applied to green card holders, the administration said that they would be assessed upon arrival, and that “swift entry” would be expected. Later it changed course and said that green card holders would not be subject to an additional check.

From 1999 to 2015, 3.6 percent of new legal permanent residents were from the seven affected countries.

Iraqis who worked for the United States government or served as translators or interpreters for the military and had been approved for special immigrant visas (SIVs) will also be allowed, and the U.S. Embassy in Baghdad will continue to process new applications. It was initially unclear whether the ban affected these visas.

The ban does not apply to some groups, including U.S. citizens and dual nationals who enter the United States presenting their passport from a country not under the ban. There was initially confusion over how these people would be affected, though the White House had told the governments of Canada and Britain that their citizens who were dual nationals of one of the seven countries would not be barred.

People on certain types of diplomatic or government visas are also exempted from the ban. Nearly 2,500 admissions from these countries were made on these visas in 2015: