From teenagers coddled by helicopter parents to underage drinkers mad for Four Loko, popular depictions of undergraduates often paint them as young adults feeling their way through postadolescence. But—while a cadre of undergraduates certainly does leave home at 18 to live on leafy campuses and party hard—many others are commuters, full-time workers, and parents.

Roughly 22 million undergraduates attended college at some point in 2007-8, and the National Postsecondary Student Aid Study from that year provides a snapshot of where students are coming from and how they pursue their educations. More than a third of all undergraduates attend part-time, and most are not affluent. That's reflected in where students go to college—more than twice as many undergraduates attend the University of Phoenix's online campus as go to an Ivy League college. You can explore students' demographics for yourself below.