Cholesterol is a waxy, fat-like substance found in every cell of the body, essential for producing hormones, vitamin D, and bile acids that help digest fat. It is carried in the bloodstream by lipoproteins, with low-density lipoprotein (LDL) often referred to as "bad" cholesterol and high-density lipoprotein (HDL) as "good" cholesterol. While the body needs cholesterol to function properly, excessive levels, particularly of LDL, can lead to health issues like Heart disease and stroke. It's important to maintain a balanced level through diet and lifestyle.