The Divine Comedy is an example of an epic poem, monumental in length and scale and divided into three sections (Inferno, Purgatorio, and Paradiso).
Dante's epic poem is subdivided into cantos (one hundred in total within The Divine Comedy as a whole), each of which ascribes to a formal meter known as terza rima. In this structure, the meter is organized into rhyming tercets (much as a rhyming couplet is comprised of two lines of poetry, a tercet is comprised of three), with the first and last line in each tercet rhyming with one another while the middle line sets the rhyme for the next tercet that will follow. Thus, in the original Italian, every canto in the Divine Comedy would have ascribed to the same rhyme scheme: aba bcb cdc, and so forth (see the reference link to the Academy of American Poets for information on this metrical structure).
This is all the more important to keep in mind given that there is no guarantee that any given translation will effectively maintain the specific rhyme scheme and metrical structure that was originally employed by Dante. Just imagine, as a point of comparison, how difficult it would be to translate one of Shakespeare's sonnets out of the original English while preserving its formal rhyme scheme and iambic pentameter, all without making serious alterations to the poem's content and meaning. The task is effectively impossible and points to one of the fundamental challenges of translation.