Before delving into the differences between each of them, it's important to know that both the NCAA, NAIA, and NJCAA are responsible for managing and organizing, each individually, collegiate sports leagues. Therefore, we can affirm that in the USA there are three types of sports leagues composed of different universities with varying functionalities and requirements.

Next, we'll detail a bit more about each of them:

The NCAA, National College Athletics Association, is the most recognized organization with a total of approximately 400 universities and, therefore, one of the most sought after by athletes who want to access university and practice their sport at the highest level. Generally, universities that are part of the NCAA tend to be the largest and most prestigious in the United States. The entry requirements for these universities and the NCAA league are much stricter and more demanding than any other league. In order of complexity, NCAA Division I is the most complex, NCAA Division II is the second most complex, although with more opportunities for international students, and NCAA Division III, the division that does not offer sports scholarships, only academic ones.

Therefore, considering Division I and Division II within the football realm, we find the number of scholarships (considered full scholarships) they can offer for both men's and women's teams:

The NAIA, National Association of Intercollegiate Athletics, is the second most recognized organization with a total of 250 universities. These universities are typically private and smaller in size compared to those in the NCAA. The admission requirements, both for the league and the university, are much more flexible than those proposed by the NCAA. Therefore, it's one of the preferred destinations for the vast majority of international students. The top universities in the NAIA would have a sports level similar to that of Division II in the NCAA. In football, both men's and women's, the NAIA offers more scholarships than NCAA Division II.

Finally, the NJCAA, National Junior College Athletic Association, is the organization comprised of all Junior Colleges in the USA (around 500 in total). Junior Colleges offer 2-year degree programs. The admission requirements, if any, are very few. This type of university is ideal for international students whose grades are not very high or whose English proficiency is not very good but who still want to live the American dream with high scholarships. The vast majority of students, after completing 2 years at a Junior College (NJCAA), transfer their credits to an NCAA or NAIA university. Many coaches from NCAA or NAIA schools look at international athletes from Junior Colleges and recruit them for their teams. In the case of football, the number of scholarships offered is very high.