Semiotics is the study of signs, codes, symbols, and signification. It is the study of how meaning is created, not what things are. Below are some brief definitions of semiotic terms, beginning with the smallest unit of meaning and proceeding towards the larger and more complex:

Signifier: any material thing that signifies is a signifier; so - a sign is a signifier, e.g., words on a page, a facial expression, the shape of the lips on a photo, an image.

Signified: the concept in your mind that the signifier refers to.

Sign: the smallest unit of meaning. Anything that can be used to communicate (or, as someone once said, to tell a lie).

Symbolic (arbitrary) signs: signs where the relationship between the thing (the signifier) and the meaning (the signified) is purely conventional and culturally specific, e.g., most words, a heart shape for love, a dove for peace, etc.

Iconic signs: signs where the signifier resembles the signified, e.g., a picture - but which can contain a good deal of 'added' meaning - for example, a photo of Madonna contains a good deal of meaning that does not really belong to the woman herself.

Indexical Signs: signs where the signifier is caused by the signified, e.g., smoke signifies fire; sweat signifies exercise, etc.

Denotation: the most basic or literal meaning of a sign, e.g., the word 'rose' denotes - at the most basic level - a particular kind of flower.

Connotation: this is the associated, secondary cultural meanings that signs and codes create, e.g., the word 'rose' signifies passion.

Metonymy: a kind of meaning or connotation wherein one sign is substituted for another with which it is closely associated, as in the use of a Union Jack flag for the United Kingdom or of the sword for military power.

Synecdoche: a way that meaning can be created by showing only a part of a thing so that it stands for the whole thing such as when garage hand means mechanic, or 'head' means 'headteacher', and so on.

Paradigmatic relations: where signs get their meaning from their close and meaningful association with other signs in the same media text, for example

Syntagmatic relations: where signs get meaning from their sequential order, e.g., the syntax or grammar (the sequence of events) that make up a story.

Myths: a combination of paradigms and syntagms that make up an oft-told story with elaborate cultural associations, e.g., the cowboy myth, the romance myth.

Codes: a combination of signs that create a meaning greater than the individual signs themselves. Codes are a kind of ' supersystem' that functions as a kind of general map of meaning - a belief system about oneself and others, which implies views and attitudes about how the world is or ought to be. Codes are where semiotics and social structure and values connect.

Ideologies: codes that reinforce ideas that tend to support existing structures of power in a society - the status quo. Ideology works largely by creating forms of 'common sense', of the taken-for-granted in everyday life.