It's not your fault if your thumb or fingers are uncomfortable when you play your flute. The problem is that the flute is a metal cylinder that rotates and rolls when you push on it, which of course you do when you play it. To keep the flute stable, flute players develop special techniques that involve putting their thumbs and/or fingers at difficult angles, and put tension on them. That's not good! And still there's not complete stability as all the fingers are involved in playing so there are always moments when the flute is likely to slip.
Flute supports are accessories designed to help you hold your flute securely while you play. No more worrying that your flute will slip in your fingers in the middle of performing a piece, or even during practice. And no more strange contortions or tension in your thumb and fingers as you try to balance the flute and play at the same time.
So, how do they work? Well, there are three different styles: