Cisco ASA Active-Active
With Active/Active failover, two ASAs can operate in a redundant fashion. If one fails, the other one can take over all ASA operations. In such an arrangement, both ASAs can forward traffic.
In contrast, Active/Standby mode allows only one ASA to forward traffic, while the other one remains idle until the first one fails.
Active/Active failover is only available to ASAs in multiple context mode.