To bend the knees in the most comfortable manner. to assume or maintain a position in which the body is supported on the feet (heels down) and the knees are bent so that the buttocks rest on or near the heels.
American Toilets make people squat with their heels up. After about 30 years, people can hardly perform the other way to squat.
To begin learning how to correctly squat, one must "hold on to something for dear life".
ME: "He squats to poop."
YOU: I tried that and just about fell on my back.
ME: "For about two weeks, he had to hold on to a chair in front of him. Squatting is difficult at first."