Hello,

The immune system is a wonderful collaboration between cells and proteins that work together to provide defense against infection.
The cells of the immune system can be categorized as lymphocytes (T-cells, B-cells and NK cells), neutrophils, and monocytes/macrophages. These are all types of white blood cells.

Namely the cells of the immune system are :

• Bone marrow
• Stem cells
• Thymus
• B-Cells
• Cytotoxic T-cells
• Plasma Cells
• Helper T-cells
• Immunoglobulins
• Neutrophils (Polymorphonuclear PMN Cell)
• Monocytes
• RBC
• Platelets
• Dendritic Cells

Talking about the most powerful immune cell it is the white blood cells B and T cells which are incredibly powerful tools in the immune system's arsenal.

Feel free to ask if you have any query
Thank you !!!