* T lymphocytes (T cells): These cells mature in the thymus and are responsible for cell-mediated immunity. They directly attack infected cells and cancer cells.

* B lymphocytes (B cells): These cells mature in the bone marrow and are responsible for humoral immunity. They produce antibodies, which are proteins that bind to and neutralize specific antigens.

Here's a table summarizing their key differences:

| Feature | T cells | B cells |

|---|---|---|

| Maturation site | Thymus | Bone marrow |

| Type of immunity | Cell-mediated | Humoral |

| Primary function | Directly attack infected cells and cancer cells | Produce antibodies |

| Antigen recognition | Recognize antigens presented on MHC molecules | Recognize antigens directly |

| Effector mechanisms | Cytotoxicity, cytokine production | Antibody production |

Both T cells and B cells are essential components of the adaptive immune system, working together to protect the body from infection and disease.