Semiotics (/ˌsiːmiˈɒtɪks, ˌsɛm-, -maɪ-/ SEE-mee-OT-iks, SEM-, -⁠my-) is the systematic study of sign processes and the communication of meaning. In semiotics, a sign is defined as anything that communicates intentional and unintentional meaning or feelings to the sign's interpreter.

Semiosis is any activity, conduct, or process that involves signs. Signs can be communicated through thought itself or through the senses. Contemporary semiotics is a branch of science that studies meaning-making and various types of knowledge.

The semiotic tradition explores the study of signs and symbols as a significant part of communications. Unlike linguistics, semiotics also studies non-linguistic sign systems. Semiotics includes the study of indication, designation, likeness, analogy, allegory, metonymy, metaphor, symbolism, signification, and communication.