Semiotics is two close things at once. It is the study of signs: not only road signs, but anything that stands for something else — a word, a picture, a red light, a brand logo, a thumbs-up. It is also, more loosely, the way people send meaning through those signs and images. A film poster, a church picture, the little cart on a shopping app: each one “says” something without spelling it out. You will meet the word in universities and among people who write about media, design, or advertising; it is not everyday kitchen talk. Though actually, the tidy idea “signs mean things” hides a mess. The same picture can mean different things to different people, and a lot of semiotics is about that gap, not about one correct reading. One more wrinkle: an English thinker, John Locke, gave the language this name, but the university subject students meet today grew much later. Teachers now mean a whole field about how meaning works, not only Locke’s old label.