It is a very important and long topic.
It depends on the person. If you don't train but you are coping, it is really not necessary. However, studies have shown that sleep deprivation affects the brain development of infants and babies who are sleep trained don't have sleep deprivation problems!
So I think it's a good thing!
How to train?
As I said at the beginning, the topic is as long as 2046, but the essential things are
Bedtime routine
Things that are repeated before each sleep session, such as closing curtains, white noise, pacifiers, soothers, blankets, bedtime stories, etc.
Bedtime routine is a way of communicating with your baby, saying "We're going to sleep! We can do this every time. As long as you do it every time, your baby will naturally learn how to train her emotions when she falls into bed.
It is recommended that the bedtime routine before sleep training is a little different from the bedtime routine of nap to avoid baby mistaking it for nap time and then waking up after two hours of training (collapse!). For example, you can take a hot shower before training, so that you can sleep comfortably.
My bedtime routine
Big Boy: dark room, white noise, blanket, pacifier (replaced by soothers after 1 year old), shower before bedtime, goodnight
Little one: dark room, white noise, blanket, singing twinkle twinkle, shower before bedtime, goodnight
Understanding the baby sleep cycle
First of all, a few cold facts for you to know: 1:
1. Babies are not born to sleep with their eyes closed, they have to learn slowly
2. There are cycles of sleep in humans, just look up the information on the internet. We are born to wake up at the end of a sleep cycle and train again, because we are naturally alert to our surroundings. As long as the surroundings are as safe/environmental as before training, we will naturally return to training. The waking time is very short, so we don't remember it first.
3. baby's light sleep period lasts about 30-45 minutes, after which he will fall into a deep sleep period. Therefore, baby does not wake up easily after training, but wakes up easily after about half an hour of training.
4. Sleep training is to train baby to move smoothly from light sleep to deep sleep, so as to achieve a good sleep. Sleep. Training. Day. Light!
Sleep on your own
baby wants to learn to fall asleep on his own, meaning that even if he wakes up in the middle of a training session, he can go back to sleep on his own without anyone intervening. Does this seem impossible? But with the right approach, they can actually do it.
The first important thing for baby to learn to fall asleep on his own is to try not to. Putting them to sleep. Sleep.
This means that there should be as little disturbance as possible from the time the baby is awake to the time he is being put to bed. The amount of cuddling, rocking and patting should be reduced gradually. All bedtime routines must be completed before being put to bed, otherwise the whole sleep train will not be successful.
*Translated with www.DeepL.com/Translator (free version)*