Explanation
Auto-failover groups is a SQL Database feature that allows you to manage replication and failover of a group of databases on a SQL Database server or all databases in a Managed Instance to another region (currently in public preview for Managed Instance). It uses the same underlying technology as active geo-replication. You can initiate failover manually or you can delegate it to the SQL Database service based on a user-defined policy.
References:
https://docs.microsoft.com/en-us/azure/sql-database/sql-database-auto-failover-group