Smiling for the first time, recognizing someone’s face, responding to the sounds for the first time, etc are the skills that refer to developmental milestones. The growth rate at early years of your baby is amazingly fast. You should be aware of what’s normal and what to expect at each stage for your baby’s healthy development.
No two babies reach milestone exactly at the same time. Your baby will develop at his/her own pace.
Keeping a track of milestones met by your little ones at each stage will help you a lot. The earlier you determine a delay in meeting the milestones, the higher the chance of getting a right treatment.