Complex systems refer to systems that are composed of multiple interacting elements or agents that exhibit emergent behavior, meaning that the behavior of the system as a whole cannot be fully understood by simply studying the individual components. These systems often display nonlinear dynamics, feedback loops, and self-organization. Research in complex systems seeks to understand how patterns and structures emerge from the interactions of many individual components, and how these systems adapt and evolve over time. This field of study is interdisciplinary, drawing on concepts and methods from physics, mathematics, computer science, biology, and social sciences. Some common examples of complex systems include ecosystems, the human brain, social networks, the stock market, and traffic flow. By studying these systems, researchers aim to develop predictive models, identify underlying principles of complexity, and design interventions to manage or manipulate these systems for desired outcomes.