Why would you use a 'vApp' template in VMware?

Using a 'vApp' template in VMware primarily serves the purpose of simplifying the deployment and configuration of multiple virtual machines (VMs) that are grouped together for a common application. A vApp is essentially a container that can hold one or more VMs, along with predefined network settings and resource allocations.

By utilizing a vApp template, administrators can create a standardized environment that includes all necessary configurations, such as resource limits, network settings, and dependencies between the VMs. This allows for consistent and efficient deployments, as the user can deploy multiple VMs with predefined settings in one single step. This is particularly valuable in scenarios where applications rely on multiple interdependent VMs, as it reduces the complexity and time involved in setting up each VM individually.

The other options, while relevant to virtualization management, do not directly relate to the specific capabilities and advantages provided by a vApp template. For instance, duplicating a single VM's resources pertains more to cloning or snapshotting rather than vApps, and automating backup processes or improving VM security settings do not directly address the main use case for vApps, which is primarily about streamlined deployment and configuration of interrelated virtual machines.