How is a symbol different from an icon in Charles Sanders Peirce’s theory of signs?

In the semiotic theory of Charles Sanders Peirce, signs are categorized based on how they relate to their referents. The fundamental difference between an icon and a symbol lies in the nature of that connection:1

• Icon: An icon functions by virtue of resemblance. It represents its referent because it shares physical or structural characteristics with it, such as a road sign depicting falling rocks to warn drivers of that specific hazard.1
• Symbol: A symbol is related to its referent solely through convention or social agreement. Its meaning is not derived from a natural likeness but from the established rules or habits of a group that agrees upon its significance, as is the case with words or specific traffic signals.12

Peirce’s work emphasizes that while icons rely on direct similarity, symbols require the active cooperation of a community to interpret the meaning behind the sign.12