How jibs attach to the forestay depends upon the forestay. If it’s just a wire or rod, the sailmaker will use hanks. If the forestay has grooves (like a Tuff-Luff, which doesn’t roller-furl)- there will be a luff rope that slides up the groove. The sail areas are different because the r/f sail’s foot has to be cut higher, to enable it to roll up without bunching and jamming the r/f fitting. Non r/f sails don’t have this problem, so they can go all the way down to the deck, adding more sail area and creating an “end plate” effect.