The three main branches of literature are prose, poetry and drama. While historically the branches were quite distinct, modern works from the 20th century and beyond increasingly feature combinations of these different forms.
Prose is typically presented in the form of novels, novellas or short stories. This type of literature is characterized by ordinary syntax contained in complete sentences, as opposed to poetry, which often features rhythmic structure contained in separate lines rather than sentences. Prose, whether in a lengthy novel or a brief story, generally conveys a complete narrative.
Compared to prose, poetry is characterized by a greater focus on language and rhythm and less of a focus on narrative. Poetry is often far more abstract than prose and has more emphasis on the aesthetic qualities of the language. Poems are typically shorter than novels and stories, though some, such as Ezra Pound's "Cantos," can span hundreds of pages.
Drama is literature represented through performance. Though written in text, it's intended to be performed by actors on the stage. Due to its performance-based nature, drama is more reliant on dialogue than other forms of literature. It's also a more collaborative art form because a play must be interpreted by a director, acted out by actors and viewed by an audience. In the 20th century, many writers began combining these forms, such as James Joyce, whose novel "Ulysses" contains elements of prose, poetry and drama.