Exposition, or expository writing, shares information or explains a subject to readers. You may have prior knowledge of a subject that you communicate to readers, or you may be required to write a combination paper in which you share your own ideas along with information you found by conducting research on the topic. Writing assignments that ask you to compare and contrast two ideas, to discuss problems and solutions, to critique an article you have read, to explain a concept or a process, to write a report, to summarize what you have learned, or to analyze issues all require an expository paper.

Expository writing should be objective (based on facts or observable data rather than opinion and undistorted by persona interpretation, emotion, or bias). Unlike personal or persuasive writing, you should not share your personal opinion about the topic or judge the information you present. Your task is simply to present it as fairly and accurately as you can. Because expository writing focuses on the subject matter, it generally uses a third–person point of view (he, she, they, the subject, the author).

The example below illustrates an expository paragraph about growing vegetables.

Growing vegetables requires planting seeds or seedlings (which are small plants) in the garden, when no threat of frost exists. Small seedlings are tender and can be easily damaged when their fine roots are exposed to air or disturbed during the transplanting process. This condition, known as "transplant shock," can prevent the plants from thriving in their new environment or may even kill them. To prevent transplant shock, seedlings should be watered with a solution of vitamin B–1 immediately after they are planted.