01
The differences
אַךְ אֲשֶׁר יֵאָכֵל לְכָל נֶפֶשׁ הוּא לְבַדּוֹ יֵעָשֶׂה לָכֶם
Hence on Yom Tov the work needed for food is permitted.
Per Beit Hillel (Beitzah י״ב ע״א (12a)) - "since it was permitted for need, it was permitted for non-need": kindling and carrying are allowed on Yom Tov even not for food, when there is some need that day.
עירוב תבשילין
When Yom Tov falls on Friday - one prepares a cooked dish and bread before the festival, permitting cooking on Yom Tov for Shabbat.