Advisor, tutor, master, sponsor, model, coach—these are six roles performed by a mentor. These roles enable the mentor to guide, equip, and encourage someone who is preparing for a professional career or other responsibility. The accomplished mentor emphasizes different roles as the needs of the protégé change, so that mentoring is dynamic and adaptive. Of course, mentors do not necessarily rationalize their work by thinking, "Today I will be more of a sponsor and model as opposed to an advisor or tutor." Rather, the idea is that reflecting on these roles with respect to the protégé's needs helps to remind mentors of the various ways they can help their protégés develop the skills and attitudes needed for career success.

Mentoring takes different forms that are often determined by characteristics of the mentor, the protégé, and the circumstances of their association. Mentoring can be formal, such as when a department or supervisor assigns a mentor to someone who was recently recruited. More informal varieties of mentoring can arise through common interests or a connection of some kind. Mentors may be master clinicians, senior scientists, experienced teachers, or leaders in a profession who share their expertise with younger or less experienced individuals. Distal mentoring is increasingly important, as mentors and protégés connect by means of the Internet or by telephone. These opportunities enable mentoring across long distances.

The tradition of mentoring is rooted in Greek mythology, when Odysseus (Ulysses) entrusted the care of his son, Telemachus, to Mentor. Mentor's name survives to this day to refer to the activity in which an experienced person takes an interest in one who is less experienced, to guide him or her to proficiency.

Over time and across circumstances, mentoring has served different purposes, such as grooming younger individuals in business, aiding nurses in the transition from classroom to ward-based training, developing research skills in graduate students, and teaching reflective and self-evaluative thinking to professionals of many kinds. In academic and professional circles, mentoring is the means to implicit knowledge about the "hidden curriculum," that is, professionalism, ethics, values, career development, financial issues, and the art of practice. This implicit knowledge complements the explicit knowledge that is found in curriculum content.

Mentoring offers mutual benefits to the protégé and the mentor. The protégé naturally benefits from the mentor's experiences and may be supported financially, emotionally, and professionally. The mentor, in turn, generally experiences career growth and satisfaction, increased productivity, new ideas, networking, and self-evaluation.