Atomicity refers to a transaction is either fully completed or not completed at all, there is no partial complete transaction. This also refers to all or none rule.
Consistency refers during transaction the integrity constraints are maintained so that the data are consistent before and after transactions.
Isolation refers to changes of one transaction are not visible to another transactions until the changes are committed, this property ensures transaction can be carried out concurrently without impacting the consistency of the data.
Durability refers to data before and after transaction is permanently stored in non-volatile memory, data is still persist despite system failure.