Turns out clarified butter, ghee, whatever you want to call it culturally, is not only useful for all cooking intents and purposes, but it is not such a little demon on your digestive system as regular butter could be.
Clarified butter is made from gently melting butter to separate the impurities, the clarified butter fat part, and the whey. What happens is you melt the butter, the bad bits foam up at the top, you skim those off once it seems like they have all come up (about 5 minutes), and then you scoop out the clarified butter from the top of the solids you see at the bottom, which is the whey.
The result? A pure butter ridden of impurities and whey, which is a reason many avoid dairy as well.
What’s more (and the most useful in culinary terms) is that clarified butter has a higher smoke point (see “Why Use High Heat Oil”), so it can reach higher temperatures when sautéing and cooking in the oven than regular butter.