I have been asked this question a lot lately so I thought I would shed some light on the subject - briefly of course.
An interior designer is anyone who has a degree in interior design or has a minimum of 11 years in the field as an interior decorator. They are qualified to work with architects and contractors in manipulating blue prints, floor plans, electrical, plumbing, etc.
An interior decorator is anyone who decorates interiors. They are qualified to design and execute window coverings, furnishings, wall treatments, and all surfaces. They usually purchase wholesale and sell at retail or work in departments stores or for design firms.
A home stager is anyone who arranges or rearranges the interior/exterior of a residential property to present that property as a marketable product.