Are all colleges a part of the NCAA?

No, not all colleges are a part of the NCAA. The NCAA is the National Collegiate Athletic Association, which is a non-profit association that regulates student athletics at colleges and universities in the United States. There are over 1,200 member schools in the NCAA, but there are also many other colleges and universities that are not members. Some colleges and universities choose not to join the NCAA because they do not want to be subject to its rules and regulations, or because they do not have the resources or facilities to compete at the NCAA level.