What does it mean when an employer wants contact information for 3 professional references on a resume?

Answer 1

The employer need contact information for three people who have worked with you an can say anything good about you. They are looking for those who can vouch for your professional demeanor.

Answer 2

I agree with the one above me. They want three people who are working right now at something prospective. Meaning, they really do not want anyone on your resume' that is working at McDonald's-not unless that said person is either a manager or an assistant manager. If they are either of those two, that means they made it up to the point to be trusted enough and has worked hard enough to get to that level. Or, if they work in some type of office environment or in some hospital, something like that.
They just do not want any reumes of people who are not working, is not going to school, are relatives, etc.
That is what that means: people who has known you for
3+ years and are working at stable jobs.

Answer 3

You need to list at least 3 people you have had a professional relationship with, (e.g., past co workers, supervisors, bosses, suboridantes) and you need to include how to get in touch with thsoe people. Your best bet is to list past supervisors and direct reports you are on good terms with.