Semiotics is the study of signs and how they convey meaning. Signs can include anything used to represent something else, such as words, images, sounds, gestures, and objects. According to the document, we are constantly interpreting signs from other people and sending signs about ourselves. However, signs can sometimes be ambiguous or misleading. The document provides examples of how signs like facial expressions, clothing, and advertisements can be analyzed using concepts from semiotics. It also discusses how the metaphor of love being like a game implies meanings such as games having winners and losers, rules, deception, and not being serious.