Final answer:
An allusion is an indirect or implied reference in a text, typically to another work, historical event, or famous individual, that enriches the text for those who recognize it. In literature, allusions can deepen understanding and create resonance by connecting knowledge across different works or contexts, like the Biblical references in Shakespeare's 'Hamlet'.
Step-by-step explanation:
An allusion is an indirect reference within a text that implies something without stating it explicitly. It often refers to another work of art, historical event, literary figure, or famous person. Poets and writers use allusions to provide a deeper understanding of the subject matter to readers who are familiar with the reference, enriching the experience by connecting different pieces of knowledge.
For example, in Shakespeare's play Hamlet, when the ghost of King Hamlet is described as being murdered by a 'serpent', Elizabethan audiences would recognize this as an allusion to the biblical story of the Garden of Eden, instantly adding layers of betrayal and sin to the narrative without the play explicitly having to detail them. This is why understanding allusions can greatly enhance the meaning of a text.
Allusions are not to be confused with illusions, which create false impressions of reality. Moreover, allusions differ from other literary devices, such as similes or metaphors, which make direct comparisons. Instead, allusions require the reader to make connections to outside contexts on their own.