Varsity Sports are a bit more complicated. Usually, you must be recruited or have gone through the recruiting process to participate in a varsity-level sport. At this level, you are an elite level athlete training over 20 hours a week and competing constantly, and traveling as well. Many hard hours are put into participating in your sport; whether it is practice, weight lifting, volunteering, study hall hours, etc.
Most varsity sports usually have scholarship athletes and non-scholarship athletes, where some of the team are receiving money for their athletic participation and some athletes are in a walk on position, where they get a roster spot, but do not receive any scholarship money.