Oil is a type of fossil fuel that comes in many types and grades, and in the crude form oil is removed from the ground. If you search oil quotes you will find that this substance can take a very long time to form, and many believe that we will run out of this fossil fuel in the near future. Many things require oil to operate, and this includes vehicles, machinery, and even some furnaces and other household appliances. The price of oil fluctuates frequently and is based on supply and demand. Right now the demand for oil is high and this translates into higher prices for gasoline and other products that are derived from oil. Many people want to stop relying on oil and switch to cleaner fuels and energy sources that do not harm the environment as much as oil can.