An agent-based model is like a mini world made up of lots of different people, or agents. Each agent has its own set of rules to follow and can interact with other agents in the model. It's like a computer game where each character follows their own set of rules. For example, an agent-based model could be used to simulate an animal population. Different agents would represent different animals with their own behaviors, like eating and moving around. By setting up the rules for each of these agents, you can see how the behavior of the animals changes over time.