In many ways, the analytical essay may be the most important essay type you learn in college. A component of the analytical essay is involved in the essays students are asked to write in every academic field. Further, students who are planning to become professionals will be regularly asked to write something akin to the analytical essay in the workplace.
Quite often, for an English class, an analytical essay prompt asks students to analyze a poem in order to explain its theme. Students usually believe that this requires them to explain what a poem means. This assumption is somewhat misled, though, since the main goal of an analytical essay is not to explain what something means, but how something means. But what, you ask, is the difference? To understand how something means is to understand the relationship between its parts and how this relationship generates meaning. An analytical essay does just this.
A more this-worldly example of an analytical essay might be a stock portfolio analysis, in which the numbers must be explained in terms a customer or client can understand. To explain what a percentage point means in a situation like this would only require writing something as simple as "You're losing money." While this is nice to know, it doesn't really help the client, who needs to understand how it is that he or she is losing money. Therefore, a portfolio analysis, as a kind of analytical essay, will need to explain the relationships between key holdings and how those relationships have affected the outcome.
Once this explanation is accomplished, of course, the client will then need to have the data interpreted. After all, providing interpretation is the primary reason analysts are paid. The interpretive portion of an analytical essay, which usually appears at the end, attempts to explain the relationship between the analysis that has been performed and the meaning of the thing being analyzed. To expand the above example, after explaining the relationship between holdings in a portfolio, the stock analyst will want to write something like "It is primarily because of the relationships between stocks A, B, and C that you are losing money."
Explaining the relationships between parts of a thing and interpreting how those relationships impact or create the thing as a whole is the primary goal of an analytical essay. Since the analytical essay is everywhere, mastering it as early as possible is essential.