Refurbished componenets have been returned to the factory by repair center by the original customer for some reason. It may have failed under warrenty or been returned for some other reason. The factory or repair center tests the unit and repairs any problems found. It is then sold at a discount and usually with a shorter warrenty than a new model.
B-stock item are components that work fine, but something happened to them somewhere along the line. They got scratched or dented, the original remote got lost, etc. The damage is generally limited to cosmetics or missing accessories. They are often sold at a discount, but typically come with the full factory warrent, minus claims for cosmetic damage. They may or may not have been sent back to the factory or repair center to be retested.
The main difference is that refurbished units have been previously sold to an end user and generally come with a more limited warrenty than a brand new unit. B-stock units have never been sold before and typically come with a standard warrenty, with exceptions for the conditions that make the item B-stock.
Actually "refurbished" and "B-stock" are two different terms that manufacturers use to describe the same thing.
B-Stock = Refurbished
Any of the circumstances that Dan mentions could be the case for merchandise sold under either name. You're taking your chances with refurbished/b-stock gear. IMO it's a chance worth taking for the savings that's afforded. I have mountains of refurbished and B-stock gear in my house.
Yeah, they are the effectively the same. You have to read the fine print t figure out what each manuf. covers under their B-stock/refurbed agreement, it changes for each. But what you call it really doesn't matter, it's the same thing...
A blem, not to be confused with B stock, is usually factory new merchandise that has cosmetic or other minor concerns and is sold at discounted prices.
A factory blem will rarely be displayed in the showroom by a manufacturer. It would not be in their best interested to represent their merchandise with a cosmetically flawed product, no matter how minor. A retailer might display blems, but then you have a demo/floor product aside from being a blem. The blems I've bought in the past always come in factory sealed boxes.
My personal experience leads me to believe that the 2 terms are not always and should not be used synonymously. I agree that B-stock is a "catch all" term that can mean anything including refurbished but refurbished means exactly what Dan said, "repair center tests the unit and repairs any problems found." The refurbed unit has been tested to meet original specifications. Since many use these terms interchangeably, I always ask.
I have bought several truly refurbished units without incident.
A retailer, distributor or manufacturer cannot sell a component that has been returned to the factory or repair center as new, it must be labled as refurbished, repaired or some other indicator that it has been worked on. I have purchased several refurbished components and IME they often are more reliable than new components, simply because they have been tested at least twice. That doesn't mean there won't be failures, but IME they are less common. My Yamaha receiver/pre-pro is a refurbished unit.
My Carver CD player and Sony universal remote are both 'blemished' and were labled as B-stock. I guess refurbished equipment could be sold as B-stock, but I've haven't run into that yet.
Components used for display or demonstration must also be labeled. Often the designation is "Open Box". My Sherbourn power amp is a demo unit.
Refurbished, B-stock and demo components can cost significantly less than the same model new in the box. This can allow someone (like me) to purchase components that might otherwise have been beyond their budget. You do need to be careful to inspect to component carefully, demo it if possible and make damn sure the warrenty allows you to return it for a full refund if it doesn't work or malfunctions. IMO the warrenty return period should be at least 30 days for less expensive items and 90 (or more) for more expensive ones. There should never be a restocking fee for returning a component that has failed or malfunctioned, whether it is new, refurbed, B-stock or demo.