Live migration allows virtual machines (VMs) to be moved between host servers without being powered off, providing very short downtimes on the order of milliseconds. This is done using shared storage, such as iSCSI or SMB 3.0, accessed by both hosts. It allows VMs to be migrated without interrupting applications. Quick migration in earlier versions required powering down VMs during migration, taking seconds. Live migration enables load balancing and maintenance with minimal impact on users.