There are 4 blood styles: A, B, AB, or O. Also, blood is possibly Rh-favourable or Rh-negative. So When you have type A blood, it's possibly A beneficial or maybe a detrimental. Which sort you might be is essential if you want a blood transfusion. And also your Rh https://www.youtube.com/watch?v=buIHtQY7fCU