Human development occurs throughout the lifespan and involves growth and change physically, cognitively, and socio-emotionally. It follows general principles like being relatively orderly and varying between individuals. Development is influenced by biological, cognitive, and social factors in a complex interaction. Approaches to development include traditional views that see little change after childhood and lifespan views that see development continuing across the entire life. Key characteristics of lifespan development are that it is lifelong, multi-dimensional, plastic, and contextual.