Final answer:
A model is a representation of a system in the real world that helps us understand the system and its properties, especially in physics where conditions are outside of those normally encountered by humans. Models are simplified versions of the real system and are different from theories.
Step-by-step explanation:
A model is a representation of a system in the real world that helps us understand the system and its properties. In physics, models are particularly useful in relativity and quantum mechanics, where conditions are outside of those normally encountered by humans.
They allow us to conceptualize and make predictions about phenomena that are difficult to directly observe or comprehend.
Models are often simplified versions of the real system, like toy cars compared to real cars. They may not always be completely accurate, but they provide a good idea of what the system looks like and how it behaves.