Granulocytes are cells of the innate immune system that are characterized by granules in their cytoplasm. The three main types of granulocytes are neutrophils, eosinophils and basophils.

They are characterized as granulocytes or agranulocytes. There are three types of granulocytes – neutrophils, eosinophil and basophils, and two types of agranulocytes – monocytes and lymphocytes.