Icon, Index, Symbol

Icons, indices, and symbols are categories used to understand how signs represent things. An icon directly resembles or imitates what it stands for (like a photo or drawing). An index is connected to its referent by a factual or causal link (such as smoke indicating fire). A symbol relies on accepted convention or agreement; its meaning is learned (like words or traffic signs). These distinctions help explain how signs communicate information and how we interpret them across different contexts.