Okay kiddo, so you know how your body has an army of cells that fight off bad germs and viruses that can make you sick? One of the important soldiers in this army is called a B-cell.
Now, sometimes just having regular B-cells is not enough to fight off dangerous germs. That's where plasma B-cells come in. Plasma B-cells are extra-special B-cells that have learned how to make something called antibodies.
Antibodies are like little warriors or soldiers that are made by the plasma B-cells. They are designed to stick to the bad germs and viruses and help your body destroy them. These antibodies are really important because they remember how to fight off certain germs if they try to attack your body again in the future.
So, the plasma B-cells are trained to make lots of these important antibodies to protect your body from getting sick. And that is why they are such important soldiers in your body's army!