The purpose of your essay is determined by your goal as a writer, as well as your subject matter. There are numerous types of essays, but essays usually fall under one of the following purposes for writing: to inform, persuade, explain or entertain.
Rhymes that contain two or more syllables.
I am not exactly sure what you mean by that but I think the answer you are looking for is:
it is a motto, usually used to bring people together. Strength in numbers. two is better than one