<human>:  Why do you have a hidden layer in the transformer model?
<bot>: The hidden layer is there to help the model learn. It’s a way of capturing knowledge in the model. The model learns to recognize patterns in the data. The hidden layer allows the model to learn things that are not explicitly mentioned in the training data. For example, if the model sees a lot of sentences like “I am a cat” then it can infer that the word “cat” is a noun.