Maybe you toss a couple tubs of Greek yogurt in your shopping cart because you've heard of its myriad health benefits, or perhaps you prefer its rich, thick texture, but do you know what exactly sets it apart form other styles of yogurt? If you're thinking it all has to do with country of origin, that's not quite right. Yogurt can be sold as Greek yogurt without actually being made in Greece; most Greek yogurt sold in the US is Greek in style only.
In short: Greek yogurt is a thicker-strained dairy product. It begins its life in the same way as regular yogurt--both are probiotic-rich fermented dairy products--and it becomes Greek yogurt after straining away a large volume of liquidy, lactose-rich whey. This is how it gets its thicker texture and higher concentration of protein, fat, and calcium.
Because it's thicker, it can be swapped for mayonnaise, sour cream, or creme fraiche to lighten up recipes. It's also the way to go when you want to add yogurts tang to a recipe, without adding too much liquid, like in yogurt-based dips.
To make Greek yogurt from regular yogurt, mimic how it's produced: line a fine-mesh strainer with cheesecloth set over the bowl, fill the strainer with regular yogurt, cover it all with plastic wrap, and refrigerate overnight or until thickened.