However, that may not always be the case. Most stores will allow you to return products for at least a couple of weeks, and as a result, these open-box items could have seen some use. They could show a little wear or cosmetic damage from their brief time in the original buyer's hands. This usually isn't a problem, but you should be aware that buying open-box means some items will used, if only lightly.
Open-box products can also be floor models, which the store has used to show the item off to customers. These can be a dicey buy, as they've probably seen a lot of use. Even if they've never left the store, the all-day use adds up, and can make the items more failure prone. If the open-box item you're looking at is a floor model, you may want to reconsider.
Whatever the reason an item has been labeled "open-box," these products usually get an inspection to make sure they're working before they're sold. This could be a thorough check of the product's functionality, or the inspection could be as basic as plugging the item in to make sure it powers on. Either way, open-box products should (usually) work, though it's worth finding out how they've been tested by the retailer. More testing can help ensure a more reliable product