Here's why:
* Expository means to explain or inform. Essays aim to explore a topic, present an argument, or provide information in a clear and concise way.
* Literary prose refers to writing that uses literary techniques, such as vivid language, imagery, and figurative language, to create a compelling and engaging reading experience.
While other nonfiction genres like biography, memoir, and history can also employ expository prose, the essay is specifically defined by its focus on explaining and exploring a particular idea or concept.