"A symbol is different from a metaphor in that a symbol is used more consistently and widely than a metaphor. Also, a metaphor is a statement (even if implied), whereas a symbol need not be a statement. The common element in symbols and metaphors is that the literal, conventional meaning is exceeded or negated by a nonliteral meaning.
Symbols may have very narrow or quite wide ranges of meaning. The range may be limited to an individual, or perhaps to a small group. People other than the individual or group will not understand that meaning of the symbol. A symbol's range may be cultural, meaning that it is known by members of cultural groups: ethnic groups, religious groups, national groups, and so on."
Source:
http://web.mst.edu/~gdoty/classes/concepts-practices/symbolism.html
I never put two and two together, now realizing that our minds grow using these things to shape how we interact with our world. So now I want to see a study of what signs and been forgotten over time because of advances in our life.