FCS, or the Football Championship Subdivision, is a term that is commonly used in the world of college football. However, there are several synonyms for the term that are used interchangeably. One of the most common synonyms for FCS is Division I-AA. This term was used before FCS was adopted by the NCAA in 2006. Other synonyms include the lower or second tier of Division I college football, non-BCS Division I, and the former NCAA Division I-AA. Despite the many synonyms for FCS, the term remains the most commonly used and recognized throughout college football in the United States.