General purpose of this lecture is to present on White Blood Cells. White blood cells are an important component of our blood system, which is also made up of red blood cells, platelets, and plasma. White Blood cells are also known as Leucocytes as they are colorless due to lack of Haemoglobin. There are about 6000-8000mm of WBC for 1ml of blood. These are also called Scavengers & Microscopic policemen. Here briefly present on types of White Blood Cells: Lymphocytes and Monocytes.