This document discusses infant development in months 0-24. It outlines key developmental milestones in motor, cognitive, and social-emotional skills during these age groups such as head control at 3 months, smiling and laughing at 3-6 months, sitting without support at 6-9 months, crawling and standing with support at 9-12 months, walking without support at 12-18 months, and speaking first words at 12-18 months. The document encourages monitoring infant progress and contacting a doctor with any concerns.