What different between 'well-to-do' and 'celebrity'?

Well-to-do, is an older term, simply meaning you come from MONEY.....or are well off yourself,   perhaps self-earned. 

It doesn't mean you are necessarily famous or well known........simply that you are rich, and can afford the finer things in life. 

Celebrity........implies you have some sort of fame........and might be recognizable  in a crowd,  because of whatever the hell it is you are "famous" for. 

It doesn't always imply wealth or class...........just that you are "well known"......for now. 

a few years back........I remember   "Honey Boo Boo" was a thing......and she was "famous"  for a bit........but I doubt anyone would recognize her in a Wal-Mart now.......and I  doubt they banked any of that sudden wealth. 

Likewise , I remember seeing her bloated whale of a mother on the red carpet at some event........... like trying to stick a pig in a sequined dress.......and while she surely enjoyed her 15 minuntes of fame.........I don't anyone is still breaking down her door for photo's or autographs these days. 

"Celebrity" can be pretty short lived. 

Joanie,  from Happy Days,  pretty much ended up a crack whore, living in a tralier  and was found dead, amongest a pile of garbage. 

Likewise, all the kids from Different Strokes.... no  doubt "stars" at the time....all met rather  tragic fates......

Dana, the girl, was hooked on drugs  and convicted of Bank Robbery, and died of an overdose. 

The elder brother, went to jail for something.....and ended up on Dancing with the  washed up, has been stars. 

and Gary Coleman, I believe died, after getting his brains bashed in, by his drug using "girlfriend" 

So ........so much for "celebrity". 

Rich and famous rich.

Well to do refers to the person's wealth and status in a community and as such is not the same as being a person who people recognize as being famous.