What is the difference between a research rank and a primary care rank in medical schools?

I looked up the top 100 medical school in the u s a and it gave me a primary care rank and a research rank. What is the difference between the two?What is the difference between a research rank and a primary care rank in medical schools?
Research schools are famous for medical research. They tend to be the "famous" schools like Harvard and Johns Hopkins. Clinical schools are ranked as being the best for training doctors who are solely focused on practicing medicine, not research. In all honestly, its kind of a abstract concept, and most of your clinical training is done in your residency anyways. Overall, the rankings are not that reliable. Evaluate schools based on individual merits rather than on "rank". Only a few people are on the committee to rank those schools, and they have their favorites.