A cover letter, as used in the job_hunting context is a document that is supposed to provide an introduction to the resume or curriculum vitae, which are the basic document employed when marketing one's own services to a potential employer. In the traditional way of doing things (when job hunters used 'hard copy' applications), the 'cover letters' was typically attached on top of the curriculum vitae or resume, thereby typically serving a cover in the literal sense of the word, to the Curriculum vitae or resume; and it is probably from this fact that it probably got its name 'cover letter'.
Body _ The body of the letter should be broken into paragraphs with a line space (don't use indents). Also, keep sentences succinct and paragraphs short. Don't use flowery language. Address only the points you need to put across. Brevity is the key. The body of the letter should be aligned left in both formats _ Closing, Sign_Off And Name