A fraternity is a social organization of male college students (although some fraternities are organized for high school students). Most fraternities are named after Greek letters and are chapters of national organizations. These national organizations typically belong to the North American Interfraternity Council. Some "local" fraternities operate on just one college campus and do not have an affiliation with a national organization. Many fraternities operate a "house" or "lodge" where their members live, dine and/or socialize.
Historically, the constitutions of most national organizations limited membership based on race or religion. However, these restrictions were eliminated in the 1960s and 1970s. Title IX explicitly allows single-sex organizations such as fraternities.