What defines a 'quatrain' in poetry?

A quatrain is defined specifically as a stanza or poem that consists of four lines. This four-line structure can adopt various rhyme schemes, such as ABAB or AABB, adding musicality to the poem while maintaining a compact form. Quatrains are prevalent in various poetic forms, including ballads and sonnets, allowing poets to convey emotions or narratives concisely.

The other definitions given do not correspond to a quatrain. The eight-line stanza refers to an octet, which is distinctly different in both line count and sometimes in rhythm and rhyme. The narrative structure described in another choice aligns more closely with traditional storytelling rather than a specific poetic form, while the poem that tells a story through dialogue implies a style of writing that focuses on conversations, which is not inherently tied to the structure of quatrains.