Early childhood spans from birth to age 5 and involves remarkable physical, cognitive, socio-emotional, and language development. Key physical milestones include walking, running, and fine motor skills like scribbling and cutting. Cognitively, children progress from sensorimotor thinking to representational thought, such as pretend play and understanding of symbols. Socio-emotionally, children develop self-awareness and understanding of emotions while learning social skills through family and peer interactions. This period lays the groundwork for further development across multiple domains.