IQF — individually quick frozen — means each piece of vegetable or fruit is frozen separately on a moving belt before packing, so the final product pours freely rather than forming a solid mass. Block-frozen product is packed and frozen together as a unit.
For a buyer, the practical difference shows up at two points: loading density in the container, and how the product behaves after thaw at your facility. IQF product is easier to portion and use in exact quantities; block-frozen is typically cheaper per kilo but requires full-block thawing before any of it is usable.
Which one to specify
Food-service and retail repackaging buyers generally want IQF for portion control. Buyers feeding the product directly into further processing — sauces, ready meals, purees — often accept block-frozen at a lower landed cost, since the whole block gets thawed and reprocessed anyway.