Answer:
1. With Infants, you have to use two fingers instead of your whole weight
2. On an infant, during chest compressions you only go about 1 1/2 inches deep while on adults you go about 2 inches
3. For an infant, you have to breathe more gently (because they're smaller)
(The ratio for adults and infants are both 30 chest compressions to 2 rescue breaths)