Rhetorical devices are used to convey a particular meaning with the aim of persuasion or provoking an argument about a topic. These devices are mostly used in an argumentative or oratory environment were eloquence is necessary. Rhetorical devices are not strongly guided by grammatical mechanics but are mainly concerned with arrangement, style, delivery, memory and invention. These devices include sarcasm, metaphors and irony among other constructs. For instance a statement by Abraham Lincoln when he stated that his political rival "dived down deeper into the sea of knowledge and come up drier than any other man he knew” is well placed to show use of rhetorical devices. This statement uses both irony and a metaphor to persuade the audience that the rival did not benefit from education.
Literary devices are used to create the compression of ideas and uniqueness of expression that envelops story in metaphor, imagery and symbolism. Literary devices are attended to directly in the analysis, interpretation and appreciation of literature while they indirectly guide, generate and enhance (foreground) feelings, moods, tones, suspense and expectations for the reader of literature, which includes theatrical drama and poetry (in poetry, literary devices are called poetic devices).
Examples of literary devices include the literary element of plot, which is the sequence of events that determines a story, and the literary technique of flashback, which reveals plot in an a-chronological pattern and generates suspense. Mood is another literary element (also called atmosphere) that governs how a reader responds emotionally to a story and its setting (compare the mood of Poe's works with the mood of Austen's works). Another example of a literary device is the literary technique of oxymoron. For instance, in the phrase “terribly beautiful” the two words are used together to add emphasis but refer to each others' opposite meaning creating an oxymoron of contradictory meaning.