An essay is a piece of writing that gives the authors own argument, or informs the reader about a particular topic. Essays can be used for literary criticism, political manifestos, learned arguments, observations of daily life, recollections, and reflections of the author. They are commonly used in formal education in the form of free response questions, and are often assigned to judge the mastery and comprehension of students. There are four main types of essays: argumentative, expository, narrative, and descriptive. Argumentative and expository essays are focused on conveying information and making clear points, while narrative and descriptive essays are about exercising creativity and writing in an interesting way. Essays can present arguments about all kinds of different topics.