Bhai.a. A sleeping baby is moving now.
b. A baby sleeping is moving now. Neither of these is natural English.
a. An ideal room temperature for a sleeping baby is warmer than for an adult, around 68F (20C).
b. The snuffling of a baby sleeping is perhaps one of the best sounds in the world.
What is the difference between a.(a sleeping baby) and b.(a baby sleeping) I'd use "sleeping baby" in those examples.
Student or Learner