Gold Plated and Gold Filled
Gold Filled is not like gold plated as there is approx 100 times more gold in gold fill, than there is on plated. Gold filled looks and usually wears as well as karat gold. Often referred to as rolled gold, gold fill is very hard wearing and should last under normal wear conditions for a lifetime. The technique is a sheet of gold is mechanically applied to the surface of the metal and is more common in the US and far east.
Gold Plated is a layer of gold applied to a base metal, usually by electroplating. This is usually a very thin layer, which is likely to wear quicker than gold filled but is more common in the UK.