Semiotics is the study of how meaning is created and communicated. In a way, we are all semiologists because we are all constantly decoding signs and symbols on an unconscious level.
For instance, take the following image;
There is a significant chance that you would identify this image as a heart. However, the image bares little resemblance to an actual heart.
The difference between the two images is understandable when you consider that the origin of the heart symbol is not, in fact based of the heart at all. In fact, the symbol may have been based off of the shape of the seedpod of the Silphium plant, which was used by the ancient Greeks and Romans as a form of birth control. It may have been this association with love and sex that popularised the shape as a symbol of love.
This is a good example of another model of semiotics, Barthes’ three levels of signification. Barthes came up with three levels of interpretation that signs can go through. The first level is that of denotation. When it was first discovered, the image of the Silphium seedpod represented simply itself.
As it’s properties became known, the image and shape took on a meaning related to sex and birth control. This is Barthes second level, connotation. Although, in the ancient city of Cyrene, the symbol could potentially have represented wealth as the city had become so wealthy from the Silphium trade that they put the symbol on their money.
Barthes’ third level is that of myth. In the middle ages, the symbol took on its current meaning, thanks, in part to Christianity. The symbol was appropriated to represent the love of Jesus Christ and it was incorporated into many pieces of art from that era.
On the off chance you weren’t aware of the symbol’s meaning, it could be interpreted through its use. For instance, the symbol on its own may not carry any particular meaning but, in the context of an image like this;
The meaning becomes more clear. If, however, I replaced the heart symbol with something else, say, a hamburger, the sentence makes no sense. This is an example of De Saussur’s paradigmatic and syntagmatic model of semiotics.
If we take the sentence, ‘I love you’, each individual word is interchangeable with any other word. Each word is a paradigm within the sentence’s syntagm. Changing one word would change the sentence’s meaning. Indeed, on a smaller scale, each letter in a word has a paradigmatic relationship within the sentence’s syntagm. Changing the o in love to an i changes the word’s entire meaning. However, the sentence I live you makes no sense and the meaning is lost