One distinguishing characteristic of many private colleges is that they are affiliated with a particular religious tradition.  In the U.S. there are Catholic, Episcopal, Baptist, Lutheran, Methodist, Christian Science, Mormon, Hindu and Buddhist colleges.  Many of the college guides will list religious affiliation along with size, location and other features of each college.  Knowing a college has a particular religious affiliation gives you some information about the history of the college and might provide some clues about its mission, but don’t assume you know what it means without further investigation.