title: Loss decreasing after each step in an epoch
body: <p>As per my understanding the loss would decrease after an epoch, but why while training a model the loss value is decreasing after each step in an epoch? Backpropagation happens only once in an epoch or does it happen at each step in an epoch?</p>
  <p>This is probably a silly question, but I couldn't find answer anywhere. If there is already a question regarding this, please post the link.</p>