There are a few key differences between butter and margarine, so those who care about what they are putting in their body will definitely want to take a look at them. Butter is a natural dairy product which is made by churning cream until it separates completely and becomes so thick that it forms a solid mass. This happens when all of the fat molecules in it start to come together. Margarine on the other hand is a completely manufactured food product which is derived from vegetable oil as well as milk, colorings, and various flavorings as well.
Typically margarine is a lot less expense than real butter and it is often healthier because it does not include all of the saturated fat that butter does. Margarine is made up of hydrogenated oils whereas butter is comprised of milk. Butter has a very high cholesterol level whereas most margarine has a significantly lower overall level. This means that typically margarine is the healthier choice for those who want to avoid gaining weight unnecessarily ingesting high quantities of saturated fat.