What is the difference between B and T cells?

Both cells are white blood cells and are involved in the immune response. There are two main responses you should be aware of The humoral response and The cell-mediated response
B cells are white blood cells that mature in the Bone marrow, they are responsible for the humoral response. This means that the B cells produce antibodies (bits of protein) which travel in the blood to combat foreign invasion.
There are two key derivatives of B cells: Plasma cells - these cells develop from immature B cells and produce antibody, Memory B cells - these cells develop from immature B cells and remain in the body to fight off future infection with the same pathogenT cells are white blood cells that mature in the Thymus, they are responsible for the cell-mediated response. This means that the T cells directly fight off foreign invasion without the need for production of antibodies. They can do this by directly killing foreign cells (cytotoxic T cells) or by helping the action of B cells in the humoral response (T helper cells).There are two key derivatives of T cells Cytotoxic T cells - these cells are involved in the direct killing of infected cells - an example is the NK cell. T helper cells - these cells are involved in helping the B cell (or humoral response)