Indexical Sign

An indexical sign is a type of sign that indicates or points to something directly, usually through a physical or causal connection. For example, smoke is an index of fire because it signals that a fire is present. Unlike symbols, which are connected by learned or arbitrary rules, indexical signs have a real-world link to what they represent. They help us infer or recognize conditions or events based on direct evidence or signs in the environment. In essence, indexical signs serve as natural indicators that something else is happening or exists nearby.