Along with Homer’s Iliad, the Odyssey is one of the two great epics of ancient Greece. Actually, they sort of defined what an epic was in the first place. Both poems display many of the epic’s characteristics, featuring a larger than life hero, deeds of great valor, and the interference of the gods in human affairs. Also, both poems use literary devices that have become typical of epics: opening with an invocation to the muse; beginning the story in medias res (basically, “in the middle of things”); providing long lists of people, genealogies, and places significant to mythological history; and using epithets, or repeated nicknames, for various characters, major and minor. For the Ancient Greeks, it was also important that an epic be written in the poetic meter of “dactylic hexameter” (see our “Writing Style” section for details) – which both the Iliad and the Odyssey are.
On the other hand, it’s important to remember that the Iliad was probably composed first, so you can see the Odyssey playing around a bit with the pattern the earlier epic established. It does this by having a more complicated plot; by including characters from lower social orders (such as Eumaios the swineherd); and by having much of the action centered around women in the home. This is probably connected with the fact that parts of the story (especially the parts recounted by Odysseus) resemble cultural folklore, involving unrealistic, mythological creatures and occurrences. These render it a player in the mythology genre and, of course, a major example of a quest (basically, a hero facing obstacles on his way to get somewhere).