What is a sign, a symbol and the difference between the two?
Signs and symbols were popularized by the French philosopher Roland Barthes through the study of semiotics, which breaks down signs into their more digestible components. Within semiotics, an image or word can be broken down into both a signifier and what it signifies. The signifier exists as the visible or obvious component that suggests a certain meaning. The signified is the meaning itself. Semiotics is the relationship between the signifier and the signified, and that relationship contributes to a broader meaning, understood as a sign. (See attached flowchart.) These signs are understood as myths, signs that are perpetuated over time based on their original symbols.
Barthes was famous for breaking down photography as a medium. Two ideas he came up with in relation to photography might help to further explain the difference between a sign and a symbol. Photographs contain, along with signifiers and their signified meanings, information that can be broken down in two ways. When considering a photo's objective qualities (framing, depth of field, subject matter), you are dealing with the concept of stadium. This concept loosely relates the the idea of the signifier, because these qualities are meaningless until we assign meaning to them. The elements of a photo that are harder to break down but hold immense emotional depth are described as punctum. These are the particular things about a photo that elicit an emotional response in the viewer and give the image meaning. In Camera Lucida, Barthes finds this punctum concept in an old photo of his late mother. There is nothing remarkable about the technical quality of the photo, but something about it captures her essence. The punctum is a feeling felt among individuals, whereas signified meanings permeate culture as a whole and are perpetuated as myths.
The theory of signs, technically known as "semiotics," dates back to ancient Mesopotamia and is closely related to theories of interpretation, known formally as "hermeneutics."
The simplest definition of a sign is something that indicates or refers to something else. The earliest study of signs was directed to "natural signs," which are interpreted in two ways. The first was causal. Two examples we find in Aristotle are "If there is smoke, there has been fire" and "If a woman is lactating, she has been with child." In these cases, a sign points backwards to the thing that caused it.
A second type of sign was divine. In Mesopotamia, for example, signs such as eclipses, the flight patterns of birds, or the shapes of the livers of sacrificed animals were thought to be signs of the gods' will. We also see this understanding of signs in Homer and ancient Greek tragedy.
A symbol is an artificial or arbitrary type of sign. For example, there is no reason that the sound "cat" should represent a small domestic feline or that a dove should signify peace. Language is a symbolic system. In literature, one often encounters symbols whose meaning depends either on cultural context (e.g. the Christian symbolism in Bunyan or Milton) or on some system of the writer's own creation (e.g. in Blake or Yeats).
A symbol is a physical object that stands for something else. An example of this could be something like the sun that stands for joy, or clouds that stand for trouble and sadness. Symbols are often used in literature, and especially poetry, to express what the author or poet wants the reader to see or feel. In this way, it is often used to help the reader experience the author’s emotion or thoughts.
Signs are more closely connected to the idea that they promote. It could be a gesture or word that directly state what might be expected. A thumbs-up sign, for example, is the universal sign that things are alright. Signs can also be words or names to provide visitors with information about shops or merchandise. Commonly, these types of signs can be street or shop names.
For a symbol, it is therefore necessary to think a little bit about the connection between the object and its meaning. This meaning is often fluid. Signs are generally less fluid and more likely to have a clearer and concrete meaning.