The theory of literary techniques involved in composing verse and prose is known as poetics. If you study poetics in college, you'll read, talk, and think about a lot of literature.
Poetics goes back to the Greek poietikos, "pertaining to poetry," or literally, "productive or creative." While poetry is evident in this word, you can use it to describe a deep study of any kind of literary work. When it's capitalized, Poetics usually refers to the title of a work by the ancient Greek philosopher Aristotle, which is the earliest known Western work of literary theory.