ELI5: Explain Like I'm 5

Model selection

Model selection is when you need to choose the best model from many different options. For example, if you were trying to predict how much rain will fall in a particular place, you could choose from various models - like linear regression, decision trees, random forest, etc. You would have to compare each model and choose the one that best predicts the rain. The evaluation criteria could include accuracy, speed of prediction, ease of use, etc.