A letter of recommendation is one that is written on behalf of a candidate by someone who can attest to that candidate's abilities in the classroom or on the job. This letter is often addressed to a hiring manager or admissions officer or USCIS officer who is evaluating a potential employee, intern, immigrant or scholarship applicant.
Recommendation letters complete an application. They achieve this by providing information about a candidate's character traits, such as integrity, intellectual zeal, or leadership potential. A great letter of recommendation from a professor, therapist, manager, or coworker can help an applicant stand out from the crowd.