Model change

Okay, imagine you have a toy car that you really like to play with. But one day, you notice that some parts of it are old and worn out. So, you decide to swap those old parts with new ones. The car still looks the same from the outside but it works much better with the new parts.

This is kind of like what happens with models. A model is a way of showing or representing something, like a toy car. Just like with your toy car, sometimes there are things about a model that need to be improved or changed so that it works better or gives more accurate results.

So, when people talk about a "model change", they mean that something about the way the model works is being updated or altered. It might be that the model is getting more information or data added to it, or that researchers have found a better way to calculate the model's predictions.

Just like with your toy car, sometimes the change to the model doesn't change what it looks like on the outside. For example, a model might still produce the same graphs or charts even after the change. But just like with your toy car, sometimes even though the model looks the same on the surface, it might be working much better with the new changes under the hood.