The B-cell response is a crucial part of the immune system that helps the body fight infections. When a pathogen, like a virus or bacteria, enters the body, B-cells recognize specific parts of the pathogen called antigens. This recognition triggers the B-cells to activate and multiply. Once activated, B-cells differentiate into plasma cells, which produce antibodies. These antibodies are proteins that specifically target and neutralize the pathogen. Some B-cells also become memory B-cells, which remain in the body to provide long-lasting immunity, allowing for a quicker response if the same pathogen invades again.