The consensus process produces a specific subset of candidate transactions which should be considered and added to the next ledger. These candidates must be agreed upon by a supermajority of the validating nodes.
Once a round of the consensus process completes, each node in the network computes a new ledger. This happens when the agreed upon candidates are added to the last validated ledger (N) and this becomes (N+1).
Validating nodes then calculate a new version of the ledger which it bases on the candidate transactions that were agreed upon in the consensus process. They then send a copy of this ledger referred to as a validation to the entire network which gives all other nodes the ability to compare the ledger they computed with those of their peers.
Once the other nodes receive the validation, they compare it with their calculated ledger and once the validation is agreed upon by a majority of the nodes in the network, the ledger is considered to be validated. This ledger now becomes the ledger in which transactions in the network are applied. In some cases, a node calculates a different result from the validation provided by the validating nodes. When this happens, the said node has to disregard its ledger computations and recompute the correct ledger.
For a ledger to be validated, it must garner a supermajority of the nodes. However, in some rare cases, this does not happen and the validation provided does not match the calculations carried out by a majority of the nodes. This usually happens when the transaction volume is extremely high causing inconsistent candidate proposals in the consensus process. When this happens, the nodes have to restart the consensus process until it produces consistent results which garner a supermajority of the nodes.
Once the new ledger is agreed upon by the supermajority of the nodes, it becomes the new validated ledger and transactions are henceforth applied to this ledger. The process is now complete and it begins again the consensus process. All the candidate transactions that were not considered in the previous round of consensus are now considered along with any other transactions that have been added to the network.