Symbolism is the act of creating a concept, thing, object, or idea that represents an abstraction or an instance of that abstraction. It should be noted that symbolism is not the same thing as creating an icon in the religious sense, which is a physical representation of something that is worshipped such as an image of a god or deity.
A blanket example of symbolism was Hitler's use of the swastika to represent the Nazi party and the domination he wanted to achieve.
The peace symbol, representing brotherhood, unity, and equality, was employed by many of the "flower children" or "hippies" during the 1950s and 1960s. A clenched fist with the palm facing the viewer--often is a symbol of the oppressed and the need to rise up and fight against those dominating forces--was employed by the Black Panthers during that same era to assert the need for aggression in the struggle for civil rights. The same clenched fist symbol was also employed by Hunter S. Thompson as a symbol for his Freak Power campaign when he ran for sheriff of Pitkin County, Colorado.
Although propaganda employs the use of symbolism, they are not the same. Propaganda is a form of communication that expresses an idea which is usually linked to a suggestive political or moral point of view.
The use of symbolism in poetry is usually in the form of a simile or a metaphor, although there are other elements of literature that can be employed to create a symbolic relationship. Anthropomorphism can be a very useful tool when developing a character or the concept of a thing that stands for something else.
The term "symbolist poet" is often applied to a number of French poets of the late 19th century, who reacted against the detailed descriptive character of the work of some of their predecessors. They included