It often contains tips and hints about the application and the school's services. It also looks better to the review board than a copy. Make sure your application is complete. Never send in an incomplete or partial application. Incomplete applications reflect poorly on the applicant and only create problems.
Most schools look for the balanced student.
Here again image is everything. A balanced student is one who has community service, a work history, clubs and organization membership, athletic interests and outside activities. Don't list everything you have done and make the list boring and repetitive. List a balance of items that show off your initiative and command of your own future and talents. Ask for help if you are unsure.