Development is defined as the act of "growing into a more mature or advanced state; advancement; expansion". We are developing throughout our lives, from the first moment of conception to the moment we die. Development throughout the lifespan can be divided into four main categories:

Prenatal | Childhood | Adolescence | Adulthood
It's extremely confusing, yes. But it covers just about everything from Piaget to Freud to Erikson to Bandura. The link provides a bigger copy which is much easier to read.