Bethany, I did a quick google search and someone said...
The main difference is that the Homeschool subscription allows up to 3 students to log-in at the same time, allows each child his/her own log-in so that their scores on the quiz's and other stuff can be kept seperate from those of the other children. So, if you have more than one child, AND they will be getting onto the site at the same time watching different videos, and/or you want to keep their quiz results separate, then the Homeschool option is probably the right one. However, if you only have one child, or your children won't be on the site at the same time, or if you don't care about the quiz results being kept separately on the site, then the Family/Home option is probably better, because it costs less.
Hope that helps.