A great essay tends to share the story of your life. It educates the admission committee about the experiences from which you have learned valuable lessons. It tells them what your thought processes are like. It displays how you prioritize things & make important decisions & gives a glimpse into your personal life. In totality, an essay should be a colorful & interesting depiction through which should paint an image in the minds of the readers and make them remember you as that person, who stands out.
The statement of purpose should convince the faculty on the selection committee– that you have solid achievements behind you that show promise for your success in your future endeavors.
Think of the statement of purpose as a composition with four different parts:
Tell them what you’re interested in, and perhaps, what sparked your desire for choosing the course. This should be short and to the point; don’t spend a great deal of time on autobiography.
Very important thing to understand over here is that, out of many, you want to highlight only those that support your aim and stance you have in your SOP. For instance, a future MBA wouldn’t want to highlight his technical learnings from his research, rather would want to highlight learnings such as leadership, team management, integrity, etc.
If you graduated and worked prior to returning to grad school, indicate what you’ve been doing: company or non-profit, your work/design team, responsibilities, what you learned. You can also indicate here how this helped you focus on your graduate studies.
Here you indicate what you would like to study in graduate school in enough detail to convince the faculty that you understand the course and how will it help you attain your life goals. Check the specific program thoroughly and align your last paragraph on the same lines. End your statement in a positive manner, indicating your excitement and readiness for the challenges ahead of you.