Semiotic theory of Charles Sanders Peirce

Charles Sanders Peirce began writing on semiotics, which he also called semeiotics, meaning the philosophical study of signs, in the 1860s, around the time that he devised his system of three categories. During the 20th century, the term "semiotics" was adopted to cover all tendencies of sign researches, including Ferdinand de Saussure's semiology, which began in linguistics as a completely separate tradition.

Source: Wikipedia — Semiotic theory of Charles Sanders Peirce (CC BY-SA 4.0)