I thought it was the Birkin bag that women lust after, no? What ever happened to fanny packs? Backpacks are far better ergonomically than any kind of shoulder bag.
Technically I believe they would be packs or rucksacks. Backpacks have internal or external frames, shoulder straps, and waist belts.
Small packs without frames are usually referred to as day packs, cause you can't stuff enough in there to go camping for days.