There are four main blood groups: A, B, AB, and O!  🤩
Blood type A has A antigens on its red blood cells, while type B has B antigens. Type AB is super special because it has both A and B antigens! Finally, type O has no A or B antigens, making it a universal donor.  🌍
Each blood type can also be positive (+) or negative (−), which tells if the Rh 
factor is present. So, we can have A+, A−, B+, B−, AB+, AB−, O+, and O−—that’s a total of 8 different blood types! Isn’t that cool?  🎉