What is the definition or description of: child development?

Established norms: Through observations of groups of kids, normative stages have been established for children, i.e. We know the approximate ages that kids begin to sit up, walk, talk, use the potty, and make compromises socially. In referring to these established norms, parents and professionals can see if individual kids are within the expected range of physical and psychological development.

From Batshaw, " The : End product of neural function that unfolds over time as a result of innate factors determined by the dna sequence & heritable epigenetic modifications that make up an individual's biological endowment & experiential influences that either affect neurodevelopment beneficially or deleteriously." quantifiable milestones & qualitative features in 3 major streams: motor, cognitive & neurobehavioral.