Centers for Disease Control and Prevention (2023)
Link: https://www.cdc.gov/ncbddd/actearly/milestones/index.html
Skills such as taking a first step, smiling for the first time, and waving “bye bye” are called developmental milestones. Children reach milestones in how they play, learn, speak, act, and move. Milestones checklists available in English, Spanish, Arabic, Brazilian Portuguese, Farsi, French, Haitian Creole, Hindi, Korean, Simplified Chinese, Somali, and Vietnamese.