Thank you so much for the correction, I really appreciate it.

“Edit” is often used about text, photos, sound recordings, films, etc.

“Modify” can be used in many contexts. You wouldn’t say “They have edited their kitchen”, but you could say “They have modified their kitchen”

Nothing really. They both mean changing, but I guess 'modify' is necessary to better, 'edit' can be changing for better or worse.