Where does the money come from

This might be super dumb question that i should know the answer to but here I am 🤷🏻‍♀️ I was reading up on FDIC and since the Great Depression banks that are FDIC are insured, most up to 250,000, to make sure if another depression happens people won’t loose their money. But how does that work? Like does the government have a fund to insure the money? Does the banks have the funds?