What's a Mental Model?

There are dozens and dozens of mental models. The more that we can understand and draw on these models, the better our thinking,. Our judgment in decision making and our ability to make predictions increases. Do you ever think about the models that you lean on most frequently? I'm going to over simplify, but it's the idea that the simplest solution is probably the most appropriate. And there are one that i use all the time, like acam's raizors.