The meaning changes with context; what a signifier represents in art might differ from its use in conversation. A cross is a signifier of Christianity, but in mathematics, it signifies multiplication.
Pro Tip 2/3
Cultural Variance
A signifier can vary in meaning across cultures, be aware of these differences to avoid misunderstanding. The signifier 'thumbs up' represents approval in many countries, but can be offensive in others.
Pro Tip 3/3
Abstract Concepts
Signifiers can stand for ideas or feelings that are not physically present or visible. The signifier 'heart' often represents love, even without a picture or drawing.