In VMware vSphere, the term VMotion refers to

In VMware vSphere, the term VMotion refers to

• the use of high definition video on a virtual machine.
• the process used to describe the movement of hard drive platters on a virtual machine.
• a zero downtime live migration of workloads from one server to another.
• the patented technology available to migrate a server from Hyper-V to VMware. 

EXPLANATION

VMware vSphere live migration allows you to move an entire running virtual machine from one physical server to another, with no downtime. The virtual machine retains its network identity and connections, ensuring a seamless migration process. Transfer the virtual machine’s active memory and precise execution state over a high-speed network, allowing the virtual machine to switch from running on the source vSphere host to the destination vSphere host. This entire process takes less than two seconds on a gigabit Ethernet network. Live migration allows you to:

• Automatically optimize virtual machines within resource pools.
• Perform hardware maintenance without scheduling downtime or disrupting business operations.
• Move virtual machines away from failing or underperforming servers. 

SOURCE

http://www.vmware.com/products/vsphere/vmotion.html