Margarine, as a generic term, can indicate any of a wide range of butter substitutes. In many parts of the world, margarine has become the best-selling table spread, although butter and olive oil also command large market shares. Margarine is an ingredient in the preparation of many other foods. In some regions people may refer to margarine as butter in informal speech, but (at least in the United States and the European Community) laws forbid food packaging to refer to margarine as “butter”. Recipes sometimes refer to margarine as oleo or as shortening.
A lubricant (colloquially, lube, although this may also refer to personal lubricants) is a substance (usually a liquid) introduced between two moving surfaces to reduce the friction and wear between them. A lubricant provides a protective film which allows for two touching surfaces to be separated, thus lessening the friction between them.