JPG's, art images, digital pictures are not NFT's, but those can be used as a component of an NFT
NFT = non-fungible tokens = crypto digital asset on a blockchain that is governed by the parameters of the smartcontract code that issued (or minted) the NFT
Some NFT's have real-world utility, i.e. a proof-ownership for a RWA real-world asset, or some have no utility at all, but only for their creative art, remember when squiggly lines or rock pictures sold for millions?
The most common utility is an NFT as crypto digital proof of a membership token for an exclusive "club" or community. Bored Apes, crypto punk, et al
I think NFT's can come back in the next bull market, when there's too much money, they go into all kinds of crypto assets
However, NFT's are very very very very very risky , sure, they may be very rewarding too, but only invest a very very very small amount and do not let it be a big portion of your crypto digital asset portfolio allocation
My 2 satoshis