At the period-end, all the accounts will be closed off, to get a Dr or Cr balance. This is shown again here, with the brought-forward (b/f) figure from the previous period shown as well:
The c/f figure makes the account balance. If it is on the Cr side, the account must have a Dr balance, as the total of Dr entries exceeds the total of Cr entries.
Closing Off All The Accounts