I'm guessing they might mean fruits that can or need to be stored after harvest. E.g. there's various kinds of apples and pears that ripen after harvest - some of them quickly, some of them take months and are good throughout the winter into spring.

Stuff that’s kept in warehouses. It’s not very climate friendly to refrigerate/heat those warehouses. But it does mean that we can all buy “fresh” strawberries in the middle of winter.