A cover letter is normally sent along with your résumé to any prospective employer/recruiter. Since recruiter would normally tend to read a cover letter before the résumé, it needs to captivate the reader and draw his/her attention to how you would be a good fit for the organization. It should also emphasize why you are applying for this job in particular.
A cover letter is generally personalized unlike a résumé. It might also be a good idea to send a cover letter even if the prospective employer does not request for one. You need to understand the requirements of the job accurately and customize the cover letter so that the recruiter is clearly impressed with you. Do not simply copy what is given in your résumé. Your cover letter should add to your résumé and not be a sub-set of your résumé. Cover letters should not normally exceed one page.
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