The personal statement essay is your chance to state your achievements and qualifications in a manner that will be compelling to admissions committees. Most of the other components of your application are numbers (test scores, GPA, etc.) or out of your control (letters of recommendation). Your admissions essay is your one chance to set yourself apart from all the other applicants with the same grades and the same test scores. You need to think very carefully about what it is about you that will make an academic program take notice and say, "I want this person at our school!"