Plate

Base metal of steel or brass which is then dipped in gold to create a thin layer. The gold is known to wear off eventually

Filled

Slightly thicker than plated, the outer layer is constructed by 2-3 layers of gold or silver

Brass is still the core material, gold / silver only make up to 5% of the total weight the jewelry

Vermeil

The base metal used has to be sterling silver, which is much better for those who have skin allergies to other base metals.

The silver is then gold-plated with a thicker layer of coating. However, the gold that is used for plated is 10k or 14k which has lots of impurities, might still cause skin allergies for sensitive skin

Full Filled

Jewelry is filled with gold / silver INSIDE OUT!

And The gold layer will not wear off, so gold actually = Solid gold