Essentially, a profile is a very condensed version of a cover letter. Without restating your entire resume, it matches your qualifications to the job requirements. The intention is to show the hiring manager quickly and convincingly that you are the best person for the job.
A resume profile is also referred to as career summary, personal profile statement, profile statement, resume summary, or summary of qualifications. All refer to profiling your key qualifications for the job on your resume.