To help you understand the symbolism of the rings, I have provided an explanation below:
The rings symbolize three things:
1. The Social Ecological Model (see images for the SEM:
https://www.google.com/search?q=social+ecological+model&client=safari&rls=en&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj1uMaotP3KAhVI6GMKHVzoAeQQ_AUIBygB&biw=1272&bih=6552. 4 Domains of Active Living: Occupations/Schools; Homes; Transportation; and Communities
3. 4 stages of life (young child, young adult, adult, and senior adult).