The School Profile is a piece of collateral put together by your school (usually a brochure or flyer) that includes information about the student body and the types of classes offered by your school, such as AP, IB, etc. It usually lists figures like graduation rate and other notable facts about the school, though each one is different.
The School Profile is a recommended component of the application, but because some schools do not have a School Profile, it is not required. You should talk to your counselor or another school administrator to find out whether your school has a School Profile. If so, you will need either an electronic version or a hard copy that you can scan. You can upload the file from the School Profile section on your Academic page.