This document provides an overview of semiotics, the study of signs. It discusses the definitions and models of signs put forth by Ferdinand de Saussure and Charles Sanders Peirce. Saussure defined the sign as being composed of the signifier and signified, the form and concept. Peirce defined the sign using representamen, object, and interpretant, referring to the form, what it represents, and the idea it produces. The document also notes some key applications and importance of semiotics in understanding how meaning is constructed and interpreted across different contexts.