Semiotics is fascinating to me but can be frustrating, too. Below I have what I hope simplifies and explains some basic concepts.
Signifier → This is what you see – includes everything in the visual world. Could be the symbols/shapes/letters C-A-T, for example. Could be this “thing” I am typing on. Remember that the word and sound to name such is not a thing but a concept.
Signified → This is the mental concept, who or what you think about following a signifier. In the case of seeing the letters (the concept) C-A-T, you (“are supposed to”) think about something more of less like the lovely creature (Dr. Trevor Lovejoy) to the right of this paragraph. Simply, you know how to process and understand what you see.
Sign → This is the result of both the signifier and signified and is the agreed upon, total sum of the constructed signs, sounds, concepts, images, objects, and the grouping of all of this. This is what, in semiotics, makes communication possible.
Signifier → Signified = Sign
One important element of semiotics is recognizing that everything revolves around cultural relativism.
For example, what we call a “CAT,” could easily be called a “DOG,” or a “LGYU.” These are mere sounds and symbols. OR “CAT” could be pronounced the way we pronounce “HEN” and still refer to the mental concept we get when thinking about a “cat.”
Another way to think about it is that both “thank you” and “gracias” mean the same things, yet originate from different languages. (“Gracias” is so common it’s almost an “English” word too now.) Another example: “grapadora” and “stapler” (the signifier) both point to the same signified object.
Semiotics make communication possible because we all agree (society has more consensus than it gets credit for!), going back to an early example above, on what “cat” (the sounds and symbols) refers to: While we’ll all see a different “cat” – different colors and sizes, probably based on personal experience, they are similar enough that communication is possible. In some case, such as with “social media” (signifier), the signified could point to mental concepts of Twitter, Facebook, etc, so sometimes more clarification might be needed.
Another interesting thing: semiotics would say that “running” did not exist until the first person used “r-u-n-n-i-n-g” (the signifier) to describe the shared mental concept of that physical action (signified). The action, of course, existed but was and is described by many different signifiers or letters.