I learned more about the publishing industry and how the company really worked at those lunches than I could have in years if I had to discover all of it myself. The coach is more of a tutor, observing your work and actions, providing comments on execution, and teaching skills which may be lacking. Coaches can come from many sources. A coach can be a colleague, a manager, or an employee, and doesn't have to come from the same function or division in which you work. For example, a coach may come from the company's personnel or training function.
Some senior executive hire an outside consultant to act as their coach.
It is critical in the coaching relationship for the coach to have opportunities to observe your work and for you to respect the coach and be open to feedback. These two roles, whether performed by one person or two, are an essential ingredient in your career development. No matter how much education and training you receive, and no matter how excellent that instruction may be, the incorporation of new skills and knowledge into your work takes time, practice, and feedback. The mentor provides guidance and opportunities for practice. The coach observes and critiques the performance and provides you with an outside perspective on your skills.