Refinishing is the process of "stripping" the old finish down to the bare wood with a chemical paste and solvents. The structural joints are then repaired. The piece is sanded with several grades of sand paper. A stain is applied to enhance the natural color of the wood. At this point, the piece can be finished with several coats of wax, varnish, shellac, lacquer, urethane, or polyester. The finish depends on the client's needs or the desired look.
Restoration is the process that most antiques should go through if a cleaning needs to be done. Dirt & wax are removed with mild solutions, then a hard wax is reapplied, usually a combination of bees wax and carnauba.
Antiques are over 100 years old. Valuable antiques were originally made of high quality or are unique or rare.
Some "designer" type furniture, for example furniture by Charles & Ray Eames, Le Corbusier, etc. or furniture made by manufacturers like Herman Miller are highly valued even though they're not over 100 years old. What makes them valuable is there iconic status for a given period of style, art, or architecture.
If concerned about the value of an antique, restore and do not refinish.
