The three types of lipids are triglycerides, phospholipids, and sterols. Triglycerides are composed of carbon (C), hydrogen (H), and oxygen (O). They are made of one glycerol and three fatty acids. A phospholipid is the same as a triglyceride but has a phosphate group (a phosphorus-containing salt) and choline (or another nitrogen-containing compound) in place of one of the fatty acids. Sterols are compounds containing four-carbon ring structures with a variety of side chains attached.