Epoch and Batch_size

[Bilal Alpaslan]

Please help me?

When do the weights and the biases of model update?

End of per batch_size or end of per epoch?

I can not understand this.
For example,
Our dataset has 1600 X_train data.
we choose batch_size = 64 and epoch = 10, What are the weights and biases updating number 1600/64=25 or only per epoch = 10?