Nearly every student has to write an essay at some point, but not everyone really knows what it is supposed to do. An essay is usually a compact piece of writing with a particular goal, be it explanation, persuasion, argument or instruction. Essays consist of an introduction, body paragraphs and a conclusion. Generally an essay has a clear point or topic which it systematically explains, clarifies and expounds upon. Writing an effective essay consists of following the writing process of pre-writing, drafting and revision.