What type of a poem is Death be not proud by John Donne and why?

"Death be not proud" by John Donne is a sonnet. The sonnet is a traditional form of poetry that consists of 14 lines and follows a strict rhyme scheme and meter. In this poem, Donne uses the sonnet form to address the theme of death and to emphasize his defiance and mockery of death's power. The structured nature of the sonnet allows Donne to carefully craft his words and directly address death in a powerful and poignant way.