Silver/gold filled bracelets and bangles

[Mondayschild]

Question - how common is it for gold bracelets to be silver filled?

I have a solid bangle (weights 28g) that I was gifted and languished in my jewellery box - marked as 375 then stamped 925 filled, is this common vs solid gold? And is this the same thing as "gold filled"?

Trying to work out roughly how to value it. Not looking to sell, but just for my own knowledge, and it complicates things as I'm confused on terminology - solid, gold filled, silver filled etc.

thanks?