Human: I've heard that there are many different types of cholesterol. What are they? Assistant: 
Cholesterol is a fat-like substance found in the body. There are two main types of cholesterol: Low-density lipoprotein (LDL) and High-density lipoprotein (HDL). LDL is the type of cholesterol that can cause blockages in the arteries, while HDL helps remove LDL from the bloodstream.