Final answer:
Expository, narrative, descriptive, and persuasive/argumentative are all types of essays, each serving a distinct purpose in presenting the writer's message or story.
Step-by-step explanation:
Expository, narrative, descriptive, and persuasive/argumentative are all types of essays. An essay is a piece of writing that aims to make a single point or present the writer's perspective on a certain topic. The different types of essays serve various purposes: expository essays aim to explain or inform; narrative essays tell a story based on personal experiences or someone else's life, including types like autobiographical narrative and biographical narrative; descriptive essays focus on detailing a person, place, object, or event; and persuasive/argumentative essays aim to convince the reader to agree with the writer's point of view on an issue.