An internship is a learning experience.
Some people learn more effectively through experience, and internships provide that opportunity.
Regardless of financial arrangements, an intern is not the same as a volunteer. An intern is evaluated on his performance in the internship position. A volunteer may perform the same tasks equally well but may or may not be self-conscious about the learning derived. As an intern, you must be self-conscious of what you are learning and strive to meet identified learning goals and objectives in order to successfully complete the experience. Student interns bring special skills, knowledge and fresh ideas to an organization.