Humoral immunity is immunity provided
by antibodies present in bodily fluid.
It is the major function of the B-cell
component of the adaptive immune response,
in contrast to cell-mediated immunity which
results from the activity of T-cells.
However of course, T and
B-cells work together.
And B-cells can function as professional
antigen presenting cells using
their MHC Class II molecules to
present peptide MHC to CD4+ T-cells.
And helper T-cells help B-cells to class switch and
differentiate into antibody-secreting plasma cells.
So these two types of immunity
if you like, humoral immunity and
cell-mediated immunity, they’re not
totally separate from each other.
They very much work together.