Question: how are ff7 and ff10 related?
Answer: In the lore-filled Final Fantasy 10 Ultimania books, FF10 and FF7 writer Kazushige Nojima goes into further detail, suggesting that the events of FF7 are thousands of years later and even on a different planet after Shinra's descendants develop a way to travel from Spira, their world, to Gaia, FF7's.