The mesosystem is a concept from Bronfenbrenner's ecological systems theory that describes the interactions between different microsystems in a person's life. Microsystems are the immediate environments where individuals interact, such as family, school, and peer groups. The mesosystem emphasizes how these environments connect and influence one another, affecting a person's development. For example, a child's experience at school can be influenced by their relationship with their parents. If parents are involved in school activities, it can enhance the child's academic performance and social skills. Thus, the mesosystem highlights the importance of these interconnections in shaping individual growth.