What type of poem is the poem, Acquainted with the Night?

Acquainted with the Night is a terza rima sonnet. It contains 14 lines divided into five stanzas: four tercets, or three-line stanzas, and one closing couplet. “Terza rima” means “third rhyme”, and is an Italian poetic form developed by Dante Alighieri (best known for his “Divine Comedy”).