Final answer:
Failover ensures the uninterrupted continuity of a virtual machine's service by creating a copy on a different host. High availability and fault tolerance are two concepts related to the implementation of failover in enterprise environments, particularly in maintaining crucial services.
Step-by-step explanation:
Failover is the process that creates a lockstep copy of a virtual machine on a different host. This redundancy ensures that, in the event of a failure of the original host, the virtual machine's connections can be shifted to the copy without interrupting the users or the application they are using. The technology behind this function is typically referred to as high availability or fault tolerance, depending on the specific characteristics and implementation.
High availability systems are designed to avoid service interruptions by employing failover mechanisms, while fault tolerance generally refers to systems that provide an uninterrupted service by simultaneously running duplicate systems. High availability (HA) setups are commonly used in enterprise environments where services and applications need to be accessible at all times.
Virtualization platforms, such as VMware, Xen, and Hyper-V, offer HA solutions that help in maintaining service continuity. These solutions monitor the health of virtual machines and their hosts, automatically moving VMs to another host in the cluster if the original host fails.