You're probably never going to curl up with a good report to read in the same way you would a good narrative essay, but reports are important as background sources of information when making an argument in an essay. What's the difference? There are several.
The commons types of essays describe their purpose: persuasive, expository, narrative, and descriptive. Essays are written to make arguments, present factual information in written format, tell a story, or describe the topic.
A report presents factual information in the way an expository essay would, but in very different ways. Expository essays generally use words to lay out their information while a report relies less on words and more on numbers and data.
An essay is traditionally structured using an introductory paragraph that includes the writer's thesis statement, which presents the essay writer's focus for their paper. At least three body paragraphs with topic sentences that relate back to and flesh out the thesis statement, plus a conclusion paragraph that sums up the writer's points complete the essay.
Reports have no universal structure as a rule, and the structure will likely depend on a professor's or employer's preferences. A report writer may include bullet points, graphs, charts, and tables to lay out data and illustrate their findings. Reports often do include an introduction and conclusion, but instead of body paragraphs that define the argument or point of the essay, a report writer presents data and then uses their written words to explain the data and what can be inferred from it rather than requiring abstract thought.
Additionally, reports generally include sections, subsections, headings, and a clear separation of ideas, while an essay traditionally requires a writer to show their organization of thoughts using only their words.
An essay writer presents their thoughts on a topic and writes a conclusion about those thoughts. It is up to the writer to determine the points they'll use to explain their reasoning and to describe how they came to that conclusion.
A report writer is usually expected to draw conclusions about the data they present and make recommendations based on that data. Reports leave little to the imagination and require very specific research. A report writer will not be flexing any creative muscles since the information they're required to include is based more on numbers and results than what the writer feels is important to explain about the topic.