worry vs. fret

Hi,
Is there any difference between "to worry" and "to fret"? From reading some books (I am remembering now Grisham's Painted House) I got the impression, that to fret is used mostly by uneducated people or kids. Am I wrong? However, I've never heard it, just read it.
Thanks a lot,
Jane

There isn't really as a technical difference, the words mean the same.

I would say that (in the UK certainly) the opposite applies to what you suggested;

Younger people ae likely never to use "Fret" in their diction as it's a word used more in past times, and less by newer generations.

My Grandmother used to say "Don't fret" quite a lot but I have never used the word in active day to day speech.

It's the same in the US. Fret is a perfectly good, non-slang word, but it is more prevalent in some dialects than in others, and is not used as commonly anymore. But it is still neutral enough to not really be a "marker" of any particular social group.