The core competencies were made to reflect the main qualities students need to succeed in medical school. These core competencies are demonstrated through your activities, so keep them in mind when choosing and participating in experiences. You do not need to achieve each competency like a checklist, but use them as a way to communicate to admissions committees that you are a competitive applicant.
Use these links from the Association of American Medical Colleges to learn more about the core competencies:
List of Core Competencies With Descriptions