In NCAA athletics as well as college football, there are three different divisions of competition: Division I, Division II, & Division III. In college football, Division I is further broken down into two subdivisions, FBS and FCS. Other names for these subdivisions include Division I-A and Division I-AA.
Football teams that reside in the top tier of college football, the FBS, have a few distinct characteristics. FBS schools can offer the most scholarships of any level at 85. They also are able to have the longest schedules of 12 games along with playoff and bowl games following. Most importantly they are the only teams allowed to compete in bowl games at the end of the season which alone generate much more revenue than any other level of college football in just one game.
The playoff system of the FBS is also distinct. A committee selects four teams that participate in the College Football Playoff at the end of the season. These four teams compete in the semifinals and the finals to determine the national champion in the FBS. This playoff generates the most revenue of any division of college football along with the other bowl games making FBS football the biggest and most known of any level of football.