Hello, in my library I have the repeated Fallout, the first in the series
Fallout (1mb part1, 683mb part2)
and
Fallout Classic (499mb)

I see this on the web, in my purchased games.
What is the difference, it seems the same but with other downloads?
Thank you

The non classic Fallout does include the high resolution patch. Not sure if Fallout classic does as well.

btw. there is already a thread regarding your question. Maybe you do find the answer that you seek there ;)
https://www.gog.com/forum/fallout_series/is_fallout_classic_different_from_tje_non_classic_release