AOAG stands for [Always On Availability Group].
The primary use of [AOAG] is for syncing multiple SQL Server instances together into a Failover safe environment. All other members are updated when the primary server is updated, so each member is ready if set as primary. Only the primary instance is used at a given time and can stay as the primary for as long as needed until it fails over to one of the other members.

The following script will check if all members have the proper settings for a safe failover when required.

In [SSMS]
Right-click on the [Listener,2433] Node.
Choose [New Query]
Copy and paste the following SQL Script into the Query window.
[Script for checking AOAG Failover settings]
select ag.name , ar.replica_server_name , ar.availability_mode_desc , ar.failover_mode from sys.availability_groups ag inner join sys.availability_replicas ar on ar.group_id = ag.group_id
Click on [Execute].

The output will be similar to this example of ours.


Name            replica_server_name        availability_mode_desc             failover_mode
SQLGroup        SQL-01\SQL19                SYNCHRONOUS_COMMIT        0
SQLGroup        SQL-02\SQL19                SYNCHRONOUS_COMMIT        0
SQLGroup        SQL-03\SQL19                SYNCHRONOUS_COMMIT        0
SQLGroup        SQL-04\SQL19                SYNCHRONOUS_COMMIT        0