So what is Greek yogurt? Greek yogurt is essentially the same as regular yogurt with the addition of one critical step – straining!
At the very end, the yogurt is strained to remove the excess watery whey, creating a thicker, more protein-dense product.
So while we call this variation of yogurt “Greek yogurt” in the U.S., you may see it called “strained yogurt” in other areas of the world.
Not all cultured dairy is yogurt, not all yogurt is Greek, and—most definitely—not
all Greek yogurts are created equal. Sure, they're all thick enough in texture and high enough
in protein to live up to the hype and health halo, but the industry's hit some sour patches.
Learn more on wikipidia