The High Availability Licenses section on the DEVICE | High Availability > Status page provides the following information:
Primary Stateful HA Licensed - Indicates if the Primary appliance is licensed for Stateful HA. Possible values are Yes or No. With Stateful HA licensed and enabled, the dynamic state is continuously synchronized between the Active and Standby units. When the Active unit encounters a fault condition, stateful failover occurs as the Standby firewall takes over the Active role with no interruptions to the existing network connections.
Secondary Stateful HA Licensed - Indicates if the Secondary appliance has a Stateful HA license. Possible values are Yes or No. Note that the Stateful HA license is shared with the Primary, but that you must access MySonicWall at https://www.mysonicwall.com while logged into the unique LAN management IP address of the Secondary unit in order to synchronize with the SonicWall licensing server.
Primary Active/Active Licensed - Indicates if the Primary appliance has an Active/Active license. Possible values are Yes or No.