A model is generally an abstract representation or a simplified version of a system or concept, created to explain, simulate, or predict aspects of that system. Models can be physical, mathematical, or computational, and they serve as tools for testing theories, understanding complex systems, and making data-driven decisions. For example, in machine learning, a model is an algorithm that has been trained on a dataset to recognize patterns or make predictions. In science, models help simulate natural phenomena to understand how they occur and predict future conditions. In design and engineering, models serve as prototypes to visualize and refine ideas before construction or production begins. Each type of model serves to distill the essential features of a complicated process or system into a form that can be more easily understood or manipulated.