What are the types of lipids?

The three types of lipids are triglycerides, phospholipids, and steroids. Each one differs from the others in terms of structure as well as function.  

1. Triglycerides - The main form of lipids in the body and in foods, triglycerides are made up of glycerol, which is a 3-carbon backbone. Three fatty acids, which are longer chains of carbon molecules, are attached to the carbon background. Triglycerides play a key role in metabolism as sources of energy and carriers of dietary fat in the human bloodstream.  
2. Phospholipids - Found in both animals and plants, phospholipids are structurally similar to triglycerides, with one important difference. In phospholipids, only two fatty acid molecules are attached to the glycerol backbone. The third carbon of the glycerol backbone is attached to a phosphate group instead. This unique structure renders phospholipid amphiphilic in nature, so it is both fat-soluble as well as water-soluble. The fatty-acid end is hydrophobic and insoluble in water while the phosphate group and glycerol is hydrophilic and soluble in water. Phospholipids are the integral part of the cell membrane, providing cells with structure and protection. They are semi permeable and facilitate the transport of fat and water in and out of the membrane. Phospholipids can be synthesized by the body itself so they don’t need to be consumed through the diet. 
3. Steroids - Steroids are lipids with a ring structure. Each steroid is composed of a core of seventeen carbon atoms arranged in four rings. Each of the four rings contains five or six carbons each. There are several different types of steroids found in animals, plants, and fungi. They vary from each other by the components attached to the steroid’s four-ring core. Steroids have two principal biological functions. Some steroids, such as cholesterol, are a key component of cell membranes. Other steroids are hormones, which are essentially messenger molecules. Steroids are synthesized in the body and do not need to be consumed in the diet.