Are you asking about the differences between the primary application and the secondary application?
The primary application is the main application, done through the AAMC, where all of your personal information like grades, volunteer work, your MCAT score, and your personal statement are gathered. Almost all medical schools get the same AAMC primary application, i.e., you only have to fill it out once - the AAMC takes care of the rest. The primary can cost a lot of money if you apply to a lot of schools.
The secondary applications are sent to you by the individual medical schools once they have received your primary application. They usually have extra information and questions they want you to answer. The questions are usually short essays, but sometimes they are even more complex than your personal statement. Every secondary is a little different. Each school charges an additional fee to accept the secondary.
