【Essay】 ,  【article】 ,  【paper】 ,  【theme】 ,  【composition】  are comparable when denoting a relatively brief discourse written for others’ reading or consideration.

【Essay】  is the only one of these terms which suggests a literary character or is included in classifications of literary types. It may designate any writing that attempts to cover a subject briefly, competently, and interestingly, whether the attempt is successful or not and whether it is intended for publication or for submission to a teacher or others for criticism. In such usage an 【essay】 is often distinguished from a short story or an argument, and though use of the word does not debar the introduction of a narrative or argumentative method, it typically has an expository or descriptive aim.

【Article】  carries the implication found in all senses of this word: that of membership in a whole without sacrifice of distinctness and individuality. Therefore  【article】 is appropriately applied only to one of the separate and in itself complete writings which make up a single issue of a journal or a magazine or such a book as a history written by different persons.

【Paper】 is applied to a writing, chiefly an informative writing, that is intended for reading (as at a meeting of a club or a learned society) or for publication (as in a scientific or learned journal) or as a college exercise especially in a nonliterary course.

【Theme】  and  【composition】  are applied to writings that are school exercises and submitted for criticism.

Although they are seldom distinguished in their use, except that  【theme】  is more often employed in colleges and high schools and  【composition】  in the lower schools, there can be a real difference in the implications of the words.

【Theme】  may imply the development and elaboration of a definite subject; its tests are chiefly adequacy, as evinced by its completeness of treatment within limitations, and readability, as evinced by its power to interest those who read it and impress its points on their minds.

【Composition】 , on the other hand, implies organization of details, facts, and ideas or sometimes of sentences and paragraphs so that the result is a unified and clear piece of writing.