How do purposes of a cover letter and a résumé differ

A resume is a document that itemizes your employment history. It summarizes the jobs you have held, the education you have attained, certifications, skills, and other quantifiable information about your background and work experience meanwhile A cover letter is written to highlight the qualifications you have for the job for which you are applying. It is used to provide the employer with additional information as to why you are a good candidate for the job. The main function of your cover letter is to show off how your qualification makes you a match for the job.