In recent decades, American universities have expanded their diversity programs to address concerns about the underrepresentation of minority groups on campus.

But over the past few years, many Republican-led states have taken steps to restrict or eliminate diversity, equity and inclusion programs and initiatives at public universities and colleges, with conservative lawmakers and groups arguing that such programs can be discriminatory to the people who are left out. But supporters of such efforts say they are necessary to promote diversity and help students from various backgrounds succeed on campus.

For some universities, the opposition to diversity programs comes at a challenging time, as they face an incoming student shortage and skepticism of the value of a college degree at today’s prices. And after the Supreme Court’s ban on race-conscious admissions last year, some educators are even more concerned about diversity on their campuses.

Here’s what to know about the efforts to limit D.E.I. programs in higher education.

By and large, D.E.I. initiatives in colleges and universities include programs, campus activities and events, curriculums, recruitment, admissions and policies that are focused on promoting and increasing the representation and participation of individuals from groups that have historically been underrepresented.

Those groups can be based on race, ethnicity, national origin, gender and gender identity, age, culture, religion, disability status, socioeconomic status and sexual orientation, as well as other aspects of one’s social identity.

Some schools also have a requirement for prospective students and faculty members to include diversity statements in their applications, meaning a written pledge describing how they would help foster diversity on campus.