In higher education, college and university rankings are determined by any combination of factors. Rankings can be based on subjectively perceived "quality," on some combination of empirical statistics, or on surveys of educators, scholars, students, prospective students, or others. Rankings are often consulted by prospective students and their parents in the university and college admissions process.
The US News and World Report is the most influential ranking in the US. Schools are split into four tiers, with the best being first, and then schools are ranked within each of tier. The first tier is reserved for only the top 50 schools and any college ranked below 50 but above the third tier is part of the second tier. The fourth tier is reserved for the bottom of the barrel colleges and universities.
Some schools are considered so far below average that they don't even garner a college ranking. These include institutions like Walden University and Axia College.