Admission to a graduate school almost always requires some sort of written statement as a part of the application. The importance of the statement varies from school to school and from field to field, but overall there is an assessment occurring of the applicant's academic worthiness via his or her communication skills.
Although the essay could be one general question, such as "what is your approach to life," most universities world-wide now break the question into six or more sections, each answer requiring somewhere between 400-600 words, the equivalent of roughly two typed pages.
SPECIFIC AND EXACT ESSAY QUESTIONS
Some graduate school essay questions either totally or partially focus on specific information. The information here tends to be goal-oriented, no small part of the rubric used to evaluate the candidate. These questions tend to be worded in a way that ask "what" questions, usually concerning your academic interests, research experiences and academic objectives.
Despite the focus on specific information, all of these questions need to be answered with your focus on goals. The trick is to not merely list your goals by answering the "what," but to provide explanations as well. The idea is to try to show how the goal developed within you or how your experiences have shaped your goal. This approach to these types of essay questions works because it provides you room to elucidate your point of view as a way of answering.
If the question focuses you on specifics within your background, such as asking you to discuss your research experiences or academic background, it's okay to answer the question with some part of your high school experiences, but it's better to focus on college or on time away from academia.
Best of all, try to answer the question in a way that says how you see the particular university helping you to achieve your specific goals.
Another way of phrasing the specific question is to ask you to describe your experience of something particular, like working with a team (or contrarily working independently).