Printed rolls
Roll stock is the printed laminate slit to your width and wound on a core. A form-fill-seal (FFS) machine forms the pack from the roll, fills it, and seals it in one pass. Vertical machines make pillow packs for chips, namkeen, sugar, and rice; horizontal ones wrap biscuits, soap, and bars.
Rolls give the lowest cost per pack, because forming happens on your line at speed. They suit high, steady volumes.
Ready-made pouches
Pre-made pouches arrive already formed: stand-up, zipper, gusseted, or flat. You fill and seal them by hand, on a simple band sealer, or on a pouch-filling machine.
They cost more per pack but need little equipment, and they give shapes an FFS machine can't easily make, such as stand-up zip pouches. They suit premium products, smaller volumes, and new launches.
How to decide
If you have an FFS machine and steady volumes, buy rolls. If you don't, or the pack needs a zip, a flat bottom, or shelf presence, buy pouches. Many brands use both: rolls for their high-volume packs and pouches for premium or smaller lines.