SPOT or STAIN ?
A SPOT IS:
Something that adds substance to fibers (oil, tar, gum, sugar, starch, and so on)
A STAIN IS:
Something that adds color (wine, colored beverages, certain medicines)
A DISCOLORATION IS:
A loss of color from fibers caused by strong alkali, urine, bleaches and the like.
A spot usually changes the texture of fibers while stains or discoloration have no texture. A blind man can find a spot (texture can be felt) but not a spot or discoloration!
To further complicate the matter, spotting and staining agents often are combined in one compound. Examples include candle wax, lipstick, nail polish, even coffee (vegetable dye called tannin) with cream & sugar.
*ninety percent of the spots on carpet can be removed completely if they are blotted and flushed immediately (within 2-3 minutes) with plain water.