ASR is primarily a disaster recovery tool and it supports replication of virtual machines across two on-premises datacenters or datacenter to Azure. The virtualisation platform on the datacenter side can be on VMWare or Hyper-V or a totally physical server.
ASR is also treated as a migration tool to move workloads from on-premises to Azure. Replicate – Bring up the Azure DR site as the live site - check operations – finally decommission the source site in on-prem.
A few partners use VM replication through ASR as an offline dataset for archive purpose too.