Free run or cage-free eggs are from hens to that are able to stretch their wings and move around freely in an open barn where they are provided with nest boxes. This is an important attribute since the urge to nest during a laying cycle is very strong in hens. Hens in free run systems may also be given dust bathing material and perches depending on the producer and the barn set-up.
Free range eggs are similar to free run (cage-free) except that hens are also given outdoor access. This has the added benefit of allowing hens a chance to forage on the grass. In the words of one farmer, "...the birds absolutely get their greens. They get the odd grasshopper, the odd bug down there, they dust bathe and flap their wings around in all the dust which is so different than in a conventional farm..."