What is callback in deep learning

In deep learning, a callback is a function that is called at certain points during the training process of a neural network. Callbacks can be used to monitor the progress of the training, modify the learning rate during training, or save the weights of the network at certain intervals. Callbacks can also be used to implement early stopping, where the training is stopped if the performance of the network on a validation set does not improve after a certain number of epochs. Callbacks are a powerful tool for customizing the training process of a neural network and improving its performance.