Upholstery Stapler
An upholstery stapler is simply a sub type of the standard class of staple gun which wikipedia describes as follows:
Staple guns may be driven by muscle power, electricity (from domestic power or from batteries ) or compressed air . Power staple guns can set staples at a somewhat quicker rate than hand-powered models, but their main advantage is that they can be used continuously for hours with comparatively little fatigue.
Obviously an upholstery stapler functions slightly differently because it uses certain types of staples that are used for furniture, carpeting or other fine requirements. You can't simply use a regular staple gun on a a nice piece of antique furniture is like using a tank for target practice. Just like you can't complete intricate painting with a paint gun you have to use the right kind of staples and stapler to get the right results.
Along with using the right stapler you must use the right kind of staples and I generally recommend a 7 fine wire series for the best results. See some of my other posts for more info on choosing the right kind of staples.