Symbol: A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. For example, a red octagon is a common symbol for "STOP"; on maps, blue lines often represent rivers; and a red rose often symbolizes love and compassion.
Compound: a thing that is composed of two or more separate elements; a mixture.
For Example: water (H2O), salt (sodium chloride, NaCl), methane (CH4).