The epic is generally defined: A long narrative poem on a great and serious subject, related in an elevated style, and centered on a heroic or quasi-divine figure on whose actions depends the fate of a tribe, a nation, or the human race. The traditional epics were shaped by a literary artist from historical and legendary materials which had developed in the oral traditions of his nation during a period of expansion and warfare (Beowulf, The Odyssey, The Iliad).
Epic Conventions or characteristics common to both types include:
The hero is a figure of great national or even cosmic importance, usually the ideal man of his culture. He often has superhuman or divine traits. He has an imposing physical stature and is greater in all ways than the common man.
Additional conventions: certainly all are not always present)
Opens by stating the theme of the epic.
Writer invokes a Muse, one of the nine daughters of Zeus. The poet prays to the muses to provide him with divine inspiration to tell the story of a great hero.
Narrative opens in media res. This means "in the middle of things," usually with the hero at his lowest point. Earlier portions of the story appear later as flashbacks.
Catalogs and genealogies are given. These long lists of objects, places, and people place the finite action of the epic within a broader, universal context. Oftentimes, the poet is also paying homage to the ancestors of audience members.
Main characters give extended formal speeches.
Use of the epic simile. A standard simile is a comparison using "like" or "as." An epic or Homeric simile is a more involved, ornate comparison, extended in great detail.
Heavy use of repetition and stock phrases. The poet repeats passages that consist of several lines in various sections of the epic and uses Homeric epithets, short, recurrent phrases used to describe people, places, or things. Both made the poem easier to memorize.