Is Overflow the same as savings?

No. A Savings pouch holds money you set aside on purpose, usually a planned amount you decide. Overflow is different. It does not have a planned amount. It just collects the money that is left over after your other pouches are filled. You can use them together by putting a Savings pouch into Overflow. Then that pouch gets its share from your Income Splitter plan plus any extra that lands in Overflow.