When the word “poetry” means “writing of poetry,” how did the word become a term for a particular genre of writing?

The term “poetics” was coined by American poet and essayist John Leland in 1872.Leland, an immigrant from England, believed that the word was a word used to describe poetry, and he coined the term for it as an alternative to the more formal “literature” term for prose.In 1874, he published The Poetics of the English