Site Recovery is used to manage and orchestrate disaster recovery of on-premises machines and Azure VMs.
However, it can also be used for migration. Migration uses the same steps as disaster recovery with one exception. In a migration, failing machines over from your on-premises site is the final step. Unlike disaster recovery, you can't fail back to on-premises in a migration scenario.
References:
https://docs.microsoft.com/en-us/azure/site-recovery/migrate-tutorial-on-premises-azure
https://www.microsoft.com/en-us/itshowcase/strategies-for-migrating-sap-systems-to-microsoft-azure