The bioecological model was developed by Urie Bronfenbrenner in the 1970s and proposes that the various systems a person interacts with over time is the main factor in development. Influenced by Lev Vygotsky, different areas (other people, environments, and influences) interact with a person and they affect development over their lifespan. The most inner circle of the bioecological model is the microsystem which is a person's closest relationships: their family members, peers, and teachers.
The next level is the mesosystem which is an interaction between different microsystems. An example of a mesosystem would be a parent's involvement with their child's school - these two microsystems (parents and the school) are interacting with one another to form a mesosystem. The exosystem are things that don't directly affect an individual but influence them indirectly: like the methods of their school system or their parent's workplace. The macrosystem is made up of the cultural and societal factors that influence development - things like cultural norms, religious influences, and laws.