First of all you would like to know what an article is and what it is about. Article us ab attempt to write meaningfully on certain theme or subject. An English composition shows your range of vocabulary, its correct use in simple, idiomatic sentences, and some knowledge of the subject.
You may be asked to write on an object like an incident, an accident, a journey, a fair, a biography, a favourite book or a visit require you to write about them step by step. You know, every situation has beginning, a middle and an end. So while writing an essay too, you have to proceed stage by stage.