Lipids "consist of glycerol attached to a phosphate group and to two fatty acids, or carboxylic acids." "Lipid is the collective name for fats, oils, waxes and fat-like molecules (such as steroids) found in the body. Their roles include: components of cell membranes (phospholipids and cholesterol)"
Source credit: www.rsc.org/Education/Teachers/Resources/cfb/lipids.htm