Semiotics is basically the study of signs. It studies the origins of meaning in the different languages of communication. It so complex that it goes deep into the languages, verbal or non-verbal, to even why think of the image of a car when we see or hear the letters c a r. There are many theories revolving this concept but only two will be discussed in this summary.

According to Ferdinand de Saussure, a semiotic theorist who focuses on the linguistic signs and developed the principles of semiology as they applied to language, signs have two aspects: signifier and signified.

Signifier are the materials that has a meaning while
Signified is the actual meaning.

For example: a sign of a male can be seen in a public restroom. The signifier is the male sign and the signified means that male can go inside that room because they are designated by the sign. Another theorist, Charles Sanders Peirce, believes that the way a ‘sign’ is interpreted, allows it to be signified which gives its meaning. His theory does not just focus on material or concrete signs, but to any kind of signs. For instance, Mamang Driver announces that the next stop is in Buendia and a jeepney passenger said “Para po” – the sign system here has been understood. The message contained in the driver’s announcement is that he will stop because of that passenger’s signal. This announcement is Pierce’s ‘representamen’. How the passenger reacts is the ‘interpretant’ or sense made of the sign. If Mamang Driver stops or carries on, that is the referent, the object of the sign. He interpreted the words “Para po” as representing a sign informing him to stop. He and all passenger know that with that sign the bus will stop – the object of the sign.

Everything around the environment are surrounded by an infinite number of signs. Peirce understood this and offered many different principles for how to categorize them according to their three triadic elements:  representamen, object and intrepretant. He then tabulated signs that led to ten different types as he proposed that signs could be classified according to the qualities, facts, laws and conventions associated with the objects. By examining the relationship between objects, interpretants, and representamens and, in particular, the way the referent determines the sign, Peirce also differentiate the three main ‘modes’  into which signs can be assigned: symbol, icon and index.

SYMBOL. Has no resemblance to the real object and is accepted as societal convention. It can only have a meaning if the person already know that symbol hence this is a matter of culture and previous knowledge. Like a dove can represent peace, a yellow ribbon can represent the Aquino Clan or Ninoy or Cory Aquino, a fist bump symbol can represent Duterte, the numbers 666 is linked to Satan, the letter R means repeat the course (for Lasallians and Benildeans) and the like. This graphic signs has no indirect link to the subject itself, but for each culture, they make meaning. For us Lasallians, we are known for the color green but it varies on the different Lassalian schools in the world.

ICONS. A clear depiction of the object itself, keeping its characteristics. The representatem resembles or imitates its signifies object. Examples are: Rizal Monument is represented by the actual physique of Rizal, the Mona Lisa painting, the Recycle Bin icon and more.
INDEX.  The index indicates something. It is connected with its meaning (not arbitrary) but unlike icon, its not the object itself. Like if we see a person with eyes closed, hands folded, it indicates that the person is praying, if we smell something gross inside the refrigerator, it indicates something is spoiled or expired and many more. Inexplicit links between these things suggest that a referential context exists outside the sign-system. As Peirce emphasized, the three forms are not necessarily mutually exclusive. According to him, semiotics was a process of understanding and not a structured system, so a sign under this model can be perceived as an icon, symbol or index, or a combination of the three depending on its use and interpretation.

Sources:

Peirce, C.  Collected Writings (8 Vols.). (1931-58). Ed. Charles Hartshorne, Paul Weiss & Arthur W Burks. Cambridge, MA: Harvard University Press.

Atkin, A. Peirce’s Theory of Signs. (2010). The Stanford Encyclopedia of Philosophy. Edward N. Zalta (ed.). Accessed December  29, 2012. Lanir, L. (2012, December 29). Charles Sanders Peirce: Symbolic, Iconic, and Indexical Signs. Retrieved from http://www.decodedscience.org/charles-sanders-peirce-symbolic-iconic-and-indexical-signs/23013

Semiotics: A Powerful Communication Tool For Designers. Retrieved from ttp://www.snap2objects.com/2009/07/semiotics-a-powerful-communication-tool-for-designers/