Essay writing is a fairly broad category under which several subsets may be found. One of the most frequently used of these is the argumentative essay. It is often used but much less often understood or properly executed. Here is a brief introduction to it that serves as an explanation of how it can be done successfully.
You don’t actually need to argue
The persuasive essay style is often mistaken for the argumentative. In that style the writer is expected to present the two sides of an argument in a way that clearly favors one. In contrast, essays that are argumentatively written have no need to show which side is right. It is better if the show no leanings but this is not always possible. Some topics may deal with the rights of a clear victim and a clear perpetrator for instance, making it difficult for the writer to not use language that points at one side having more weight than the other.
Your points require evidence or some other support
This type of mistake is very common among new essayists but it can also be found among older ones. It starts when someone is so certain of their knowledge that they present their opinions as facts rather than quoting trusted sources. This can lead to a paper that is composed almost entirely of fluff. A good teacher might explain why the essay was not acceptable or simply leave it up to you to discover why that style would not be acceptable.
It can still make a point
Even though both sides of the argument should be shown in a balanced way, argumentative essays can have a definite point. This point should be arrived at through sober discourse and not the emotive pleas so common in persuasive writing.
Like most things, there is more that could be said bout these essays than can be explained in a single article. In any case, you are on your way to understanding.