A cover letter, covering letter, motivation letter, motivational letter or a letter of motivation is a letter of introduction attached to, or accompanying another document such as a résumé or a curriculum vitae.
Job seekers frequently send a cover letter along with their curriculum vitae or applications for employment as a way of introducing themselves to potential employers and explaining their suitability for the desired positions. Employers may look for individualized and thoughtfully written cover letters as one method of screening out applicants who are not sufficiently interested in their positions and/or lack necessary basic skills. Cover letters are typically categorized according to two purposes:
- applying for a specific, advertised opening (“letter of application”)
- expressing interest in an organization when the job seeker is uncertain whether there are current openings (“letter of inquiry”) 
Students are often asked to submit a cover letter for an internship application. Such cover letter should include examples of extracurricular and academic experience. Despite this specific information, cover letters for internship should have a standard business letter format.
- The application letter, which responds to a known job opening.
- The inquiry letter, which inquires about possible positions.
Résumé cover letters may also serve as marketing devices for prospective job seekers. Cover letters are used in connection with many business documents such as loan applications (mortgage loan), contract drafts and proposals, and executed documents. Cover letters may serve the purpose of trying to catch the reader's interest or persuade the reader of something, or they may simply be an inventory or summary of the documents included along with a discussion of the expected future actions the sender or recipient will take in connection with the documents.
- Yate, Martin John (2004). "What Is a Cover Letter?". Cover letters that knock 'em dead (6th ed.). Avon, MA: Adams Media. pp. 1–6. ISBN 978-1-59337-107-4 – via Google Books.
- "Cover Letters". MIT Global Education & Career Development.
- "Cover letter types and samples". Career and Professional Development. Virginia Tech, Division of Student Affairs.
- Enelow, Wendy S.; Kursmark, Louise (2004). Cover letter magic: trade secrets of professional resumé writers (2nd ed.). JIST Works. ISBN 978-1-56370-986-9.