Semiotics

Semiotics is the study of nature, types and functions of signs. The study of signs has achieved great importance in the context of communication theory. A sign is any element that is used to express a physical or psychological reality, on this relationship the first one works as signifier compared to the second, which is the signified (or referent), the relationship between signifier and signified can be of two types: denotation and connotation. A traffic signal, a noise, a gesture are all examples of signs. These signs mean nothing without a code that will establish the relationship between both of them, therefore making possible the interpretation of signs. Each community develops its systems of signs and their codes in order to facilitate communication among the members. Many codes have been established in human societies, being the language the most important code (spoken and written) and the non-verbal codes, the creation of verbal signs preceded the creation of non-verbal signs. The signs provide the meaning to define or refer to everything we have learned through the senses, and what we think we know or think we want: the signs allow the conceptualization (the formation of an idea about a reality not present), they strongly influence the human behaviour and our perception of the world.

Source

http://www.aber.ac.uk/media/Documents/S4B/semiotic.html

http://www.uvm.edu/~tstreete/semiotics_and_ads/introduction.html

http://www.answers.com/topic/semiotics