What is exactly am I expected of the essay, and how is it graded?

SAT basically tests for three areas on the Easy; - Reading - Analysis - Writing skills These three areas tests how well you can you can comprehend the central idea of the source text, how good you can analyse the source text and your writing style and choice of words. these three areas are graded separately on a scale of 1-4. For example, for an essay score of 3/2/4, this means that your Reading was scored 3, your analysis of the source text was scored 2, and your writing style and choice of words was scored 4.