What does development proceeds toward greater complexity self-regulation and symbolic and representational capacity mean

Development proceeds towards greater complexity-
A pervasive characteristic of development is that children's functioning becomes increasingly complex—in language, social interaction, physical movement, problem solving, and virtually every other domain.
Self regulation-
controlling one's behavior, emotions, and thoughts in the pursuit of long-term goals. More specifically, emotional self-regulation refers to the ability to manage disruptive emotions and impulses.
symbolic and representational capacity-
something visible that by association or convention represents something else that is invisible

i may have all this wrong i’m not sure what you’re studying or what lesson you’re in

Not the answer but here is the graph.