Here's why it's considered a poem:
* Written in verse: The entire work is written in terza rima, a complex Italian verse form. This form uses three-line stanzas with a specific rhyme scheme (ABA, BCB, CDC, etc.).
* Focus on rhythm and rhyme: The use of rhyme and meter contributes to the poem's musicality and its ability to evoke strong emotions.
* Lyrical language: Dante uses vivid imagery, metaphors, and symbolism to create a powerful and memorable experience for the reader.
Although it's a very long poem (over 14,000 lines), it tells a story, making it a narrative poem.
So, while the Divine Comedy is a complex and profound work, it's definitely a poem at its core.