According to the NCSA, a Newborn Care Specialist is explicitly trained in all aspects of newborn care and will have many years of experience with families during the first few months with a newborn. They will be able to help parents feel confident in their care of their precious newborn and will be familiar with common issues such as reflux and have proven solutions and resources to help.
Postpartum Doulas will generally take care of the whole family (including sibling care), provide newborn care and education, and breastfeeding support. Some PPD cook or meal prep for the family, do light housekeeping, dishes, family laundry and run errands. Some PPDs have additional training in sleep conditioning and sleep training. However, every provider's services can vary.
"Night Nurse" is what most people think of when it comes to Newborn Care Specialists and Postpartum Doulas. Modern Night Nurses have medical backgrounds and degrees in nursing. They're a great fit for families with medically fragile babies who require more extensive training than most NCS' and PPDs possess. They don't usually have experience with sleep conditioning or sleep training, but some Night Nurses may have taken additional courses and can provide these services.
Night Nannies are similar to daytime Nannies. They generally don't have any formal newborn training, and they work under the direction of the parents. Most offer typical baby related duties, but don't provide newborn education, sleep conditioning, sleep training or breastfeeding support.