You've heard all your life that you can't tell a book by its cover. While this may be metaphorically true for some publications and people, it's not the case for resumes. A cover letter is the basis for your employer's first impression. It invites your reader to examine your resume thoroughly. From glancing at your cover letter, your prospective employer gleans information about your personality, your communication style, your attention to detail, and your professional qualifications. This section examines the relationship between your resume and the letter that accompanies it.