Crouching refers to low poses in which the knees are bent. A knee can also optionally touch the floor, as in kneeling. Also, possibly one or two hands can be touching the ground. A crouching position can be asymmetric or symmetric.
Squatting is a special case of crouching in which the knees do not touch the ground and in which the legs are symmetric.
Sometimes the on-all-fours position is also considered a kind of crouching.
Crouching in sexuality
Crouching is a possible pose for enemas, for prostate massage and for using anal sex toys on oneself because the pose makes it easy to relax one's anal sphincter. Squatting is also a natural pose for defecation in both genders, and for urination in women.
Squatting is also an element in twerking.
Crouching in spanking
Crouching can also be the pose of a spanker when the spankee is positioned low, such as lying on the floor or on all fours. It is also possible to crouch in order to spank a small person such as a child who is standing, underarm or laid over one knee.