1. Signifier Signified RED LIGHT STOP
Signifier: the material thing that is being used to represent the concept.
Signified: the concept being signified by the material thing.
Signifier
RED LIGHT
Signified
STOP

2. An Icon has a physical resemblance to the signified, the thing being represented. A photograph is a good example as it certainly resembles whatever it depicts.
An Index shows evidence of what’s being represented. A good example is using an image of smoke to indicate fire.
A Symbol has no resemblance between the signifier and the signified. The connection between them must be culturally learned. Numbers and alphabets are good examples. There’s nothing inherent in the number 9 to indicate what it represents. It must be culturally learned.

3. Barthes believed that the understanding of signs changed depending on cultural and social background.
This symbol means different things to different cultures at different periods in time: