So, what is a cover letter? A letter with additional detailed information about you, on why you are qualified for the job. You should include specific information on why you’re a strong match for the employer’s job requirements. It actually is a sales pitch of yourself and skills.A cover letter usually, accompanies your resume you send out. Possible employers use them as a way to screen you, and determine if they would like to interview you. Cover letter is from the 50s, it’s an old idea that has to be retired.