The first may be ground or not. The last two should be the same thing.

Ginger comes in many guises. Fresh, of course, which is the rhizome, or underground stem, that is harvested after the above-ground part of the plant dies away. It may be crushed, ground, and strained to produce ginger juice. It may be cooked in a sugar syrup to produce candied or crystallized ginger. It may be preserved in chunks in a sugar-salt mixture, and called preserved ginger. It may be made into preserves, like fig preserves or strawberry preserves. It may be preserved in sweet vinegar, sliced and used as pickled ginger with sushi. It may be pureed, blended into an oil, and sold as a paste condiment.

Some of these ginger products are harder to find than others. In general, an Asian market may be the best option for some of the less common ones. We have found some products in Asian markets that we have not been able to find online.

Within a few weeks, someone will probably have come up with a new way to process, package, and market ginger.

But as to your question – ginger can be dried in bits, chunks, coins, and other shapes, without being ground. It can also be ground to a powder after being dried. Ground or powdered ginger is more common – and called for more often in recipes – than dried pieces of ginger. It may be that some producers grind dried ginger more finely (powdered) than others (ground), but in general, there should not be a difference.

Ground ginger is said to be second only to salt in importance in Asian cooking.