Final answer:
Flex-box has source order independence, and the order property controls the order of flex items.
Step-by-step explanation:
Flex-box has a feature called source order independence, which allows you to move around items regardless of their order in the HTML. The order property is used to control the order of the flex items, with the value being a number. By default, the order is set to zero. Values above zero will make the item appear later in the flex container, while values below zero will make it appear earlier.