Graphics difference in downloaded games?

Wanted to ask if it made a difference if I downloaded the game from the PlayStation in the Playstore, if there were graphic drawbacks as if I had bought it on disc? Respectively. Are there graphical differences between downloaded games and games on the disc?

But I mean the same game, once downloaded and once on disc.

No. Why should it be?

I thought the disc was used as an additional storage medium for graphics etc. Is everything saved on the hard drive instead?

No, it looks exactly the same.

Yes exactly