What are the two types of fat that contribute to the structure of the plasma membrane?

I would like to clarify the question a little bit. There are two main types of fat that contribute to the structure and function of a cell's plasma membrane. The two major categories are the phospholipids and the glycolipids. A relatively quick and easy way to identify the difference between the two fat types is that the phosopholipids (as the name indicates) contain phosphate, and the glycolipids do not contain phosphate. The phospholipid usually forms up in a "bilayer" consisting of hydrophobic tails and a hyrdrophilic head. This structure helps aid in passive transport mechanisms like diffusion and osmosis. Glycolipids are lipids that have a carbohydrate (sugar) attached to it. Their role is to help with the overall stability of the cell. They extend from the bilayer into the extracellular environment.