“Sleep training” refers to helping your baby learn to fall asleep and go back to sleep by themself. Nearly all healthy babies can begin to sleep train by the time they are three months in age.
There are various approaches to sleep training including “crying it out”, the Ferber method, and the “checking method”. Some parents worry that letting your baby cry when they wake up at night can be harmful, but extensive research has not found any negative effects. To the contrary, learning to “self-soothe” is a developmental skill and an early step in teaching them to be able to manage their emotions over time. It also generally results in better sleep for the parents.