Allusion is a reference, within a literary work, regarding a film, a piece of art, a historical even, or mythology. An allusion as a kind of shorthand, drawing on the outside work to provide greater context or meaning to the situation being written about.
One can use allusion to achieve a well-rounded feel to their essay. You can reference to a multitude of other works to give your essay a more complex meaning. Making connotations to other things such as art of mythology can strengthen the point you are trying to get across. Also, using allusion may also provoke your reader to do research on a reference you are making, thus giving your essay more depth.
Hope I helped :)
