The thing to remember about fat is that it is only bad in excess of the recommended daily allowance. In fact, thrity percent of your calories should be from fat. There are three types of fat componds. Triglycerides are used to make adipose tissue and are burned for energy. Phospholipids transport hormones and fat soluable vitiams through the blood stream.
Sterols are fat compounds with no calories, such as alcohol.
Fat is separated into three catagories. Saturated fat is the least healthiest. It is characterised as being a solid in room temperature and hardens chilled. Monounsaturated fat is a liquid at room temperature, but becomes much thicker when chilled. Polyunsaturated fat is always a liquid.