Water and cells are the primary components of the human body. Many cells together form the muscles, bones, skin and other organs. While some cells remain at one place, some cells move all over the body with the circulating blood. A complete blood count test or CBC test, called in short, provides information on these circulating cells. The blood sample is collected, and the analysis is performed in a lab. This test gives information on Red blood cells, White blood cells, and Platelets. To make the proper functioning of the body, each type of blood cells need to perform well, and they have their own set of functions.