Symbol

Definition: A symbol is a phrase or picture that represents something.

Example:
A dove is a symbol of peace and a heart is a symbol of love.

Significance:  Symbols are important because it makes the reader think and could be used as a more meaningful way of comunication.  A symbol can make a reader think outside of what the picture truley is.  For example, a dove might represent peace to some people, but it could mean serenity to others.