Though people sometimes use them interchangeably, a letter of recommendation and a letter of reference actually are quite different.
Of the two, a letter of reference tends to be more generalized. It typically starts with an informal greeting — like “To whom it may concern” or “Dear hiring manager” — and helps someone get an entry-level job or apply for school. Often, you can reuse letters of reference, at least until you gain more work experience.
A letter of recommendation also helps someone apply for a job or school, but it’s geared toward a specific job or a specific school. Letters of recommendation begin with a formal greeting addressed to the decision-maker and include clear-cut, relevant reasons explaining why the applicant is perfect for the particular position, school, or program. Because of their specificity, these letters aren’t reusable.