Simple definition
Hyper-V Live Migration moves a running virtual machine between compatible hosts, usually with only a brief service interruption.
Technical operation
Hyper-V transfers guest memory and runtime state in stages. Memory pages changed during copying are sent again before execution switches to the destination. Networking, processor compatibility, authentication, and host requirements depend on the deployment.
Live Migration is not the same as storage migration: runtime may move while VM disks remain on shared storage, whereas a storage move copies disk files. Not every live-migration arrangement requires a failover cluster.
Practical example
For example, an administrator moves a running VM from host A to host B before host A maintenance, provided the infrastructure is configured accordingly.
Best practices and limitations
Verify virtual-switch connectivity, bandwidth, permissions, and CPU compatibility. Monitor failed migrations and maintain backups. Live Migration alone does not provide automatic high availability.