Unlike simulation, modeling is not an imitaion of an event, but rather a representation of objects or phenomena that exist in the real world. Simulation can exist in the realm of fantasy, wheras most modeling examples focus on occurences in the real and natural world. These are concepts that are known, which means the outcome of the model remains unchanged. Simulations, on the other hand, allow a variety of alternate endings. This is because simulations require the user to construct information, while models present the information. That is why the most common models found on educational websites are the life cycles of animals (see Life Cycle of a Frog below), procedures, or patterns like weather patterns, as information is presented and modeled to students.