In this video, the teacher discusses the fundamental poetic devices of alliteration, assonance, and consonance. They explain how these devices create rhythm and rhyme in poetry and provide examples from famous poets such as Walt Whitman and Edgar Allan Poe. The teacher also introduces the concept of free verse poetry, which breaks away from the traditional rules of meter and rhyme. They discuss the works of poets like Walt Whitman and William Carlos Williams, who embraced free verse and allowed for more creative expression in their poetry.