There are different conditions involving “used” Sony A6000 and “refurbished” Sony A6000. A refurbishment is the reconditioning to be as good as new. Used Sony A6000 are normally sold by individuals “as is”.
Refurbished Sony A6000 have multiple contexts surrounding the reasons for their refurbishment. Maybe something was seriously wrong with it or maybe it was an open box. Some people have skeptical feelings about buying cameras that had serious issues. The great thing about it is you would never know the difference from a glance or from using it. Rebuilt cameras will generally have fewer problems than used ones.
In contrast, used cameras will not go through any of the steps taken to refurbish a Sony A6000. It is virtually impossible to tell if the Sony A6000 refurbished is in good working condition, at least not in advance. It would not take long for used Sony A6000 to achieve defective components.
With refurbished cameras, each unit will come with a limited warranty. The provisions on each will vary from company to company. Most of them come with each important component covered. Many suppliers will offer warranties lasting up to three years with options to extend them.
Now with “as is” Sony A6000, if something goes wrong with the camera, in most cases, you will not be able to get your money back from the previous owner. There is no protection with used Sony A6000 and warranties are scarce.
Most Sony A6000 refurbished will come with loaded with the basic necessities.