Silver plated refers to jewellery created by covering a base metal, such as copper or brass, in a very thin layer of sterling silver. The coating can be anywhere from 1 micron to 10 microns thick.
Imitation jewelry are accessories that are made using a variety of artificial materials. It is also called 'fashion jewelry', perhaps because this is the jewelry type that allows people to experiment with different styles and trends in the most cost-effective way.