A model is a general idea of the problem we are trying to solve.
For example, a model cat would be any cat. Not a specific cat with a long tail and short fur - the model represents all cats. From our model of cats, we can learn what any cat looks like, using the patterns all cats share.
Similarly, when baking a cake, a model cake wouldn’t be a specific cake, like a sponge cake or a fruit cake. Instead, the model would represent all cakes. From this model we can learn how to bake any cake, using the patterns that apply to all cakes.
Once we have a model of our problem, we can then design an algorithm to solve it.