A cover letter is an opportunity for a job applicant to introduce himself to a hiring manager and to offer details about qualifications beyond those presented in a resume. The term "cover letter" refers to its use as a lead-in to a submission of application materials, including a resume.
A cover letter also allows the writer to explain qualifications in a more organized and detailed way than what is possible on the application or resume. A compelling cover letter often describes the credible experiences and qualifications the applicant can apply to specific responsibilities of the job. The cover letter also includes contact information and a call to action to motivate an interview call.