You understand neither volunteer status nor unpaid internships.

An unpaid internship is a position of some authority that resides within the hierarchy of the corporate structure. Internships have always been on the career path to greater responsibility. An intern is assumed to have the necessary specialized skills to perform an aspect of the job and the internship is seen as a low-pressure environment to refine one's specialized skills in order to improve their value. It's only since 2008 that the former (low) paid internships have become unpaid internships; as with low-paid internships, the unpaid internship comes with the implicit guarantee that any paid position for which the intern is qualified will be offered to the intern first and foremost.

A volunteer position is a position of no authority in which the volunteer is assumed to have a specialized skillset outside of the primary goal of the volunteer position. No career advancement is offered or implied and the volunteer labor of the intern is presumed to be secondary or tertiary to the principle labors and responsibilities of the volunteer. Further, the volunteer offers her services out of altruism, not self-interest; there is no quid pro quo assumed between the volunteer and the organization she volunteers for.

Call up your local political party. Tell them you want to volunteer. They'll sit you at a phone and have you make calls. Or instead, tell them you want an internship. They might ask for a resume. If they like it, they might bring you in for an interview. They might have you compete for your unpaid position amongst other unpaid, qualified candidates. Should you get the job, you'll be in charge of the very same phone bank, getting the exact same money. But at the end of the campaign, your performance as a political operative will have either endeared or alienated people you are working for. Meanwhile, the volunteers will go back to their day jobs.

Interns can be fired. Interns can be held responsible. Interns are subject to (some) labor laws. Interns are judged as employees, albeit cheap ones. Volunteers? Volunteers answer phones and canvass neighborhoods.

Got a buddy. He's now an executive at Disney. I'm not. The difference?

He could afford to spend three years as an unpaid intern.