Semiotics is a big word that means "studying signs and symbols." Signs and symbols are things that we see or hear that give us a message. Like a stop sign, which is a sign that tells us to stop.
Fashion is the clothes that we wear. We wear clothes to express ourselves and to show who we are. Think about wearing a superhero cape - it tells others that you are pretending to be a superhero.
But clothes also have hidden messages. They can tell us things about the person wearing them, like their job or their social status. For example, a doctor might wear a white coat to show that they are a doctor.
So the semiotics of fashion means studying the hidden messages that clothes give us. We can look at the color, texture, and design of clothes to see what they are trying to tell us. For example, a black suit might mean that someone is going to a funeral, while a colorful dress might mean that they are going to a party.
By studying the hidden messages in fashion, we can learn a lot about how people use clothes to communicate and express themselves. It helps us understand the world around us and how we fit into it.