Answer:
Models
Explanation:
Models are abstractions of the real world. Models helps to mimick what is actually the true representation of a body. It is easier to work with models because they are our own creation. This makes them flexible to carryout any form of adjustments and manipulations. We can try out a model with different variables to simulate an obtainable result.
Models are easier to work with than the complex reality with a lot of factors and conditions that may not be easily predictable and under control.