When searching for a job, you need to think about more than just your resume. The cover letter completes your self-marketing job search package. The purpose of a cover letter is to provide potential employers with additional information about your skills, abilities, and experience — and tell them why you are uniquely qualified for the job. A well-written cover letter showcases your communication skills, is concise, and does not use overly formal language. When crafting your letter, there are three types to consider.