Which component allows pooling and management of resources across multiple hosts?

The component that facilitates the pooling and management of resources across multiple hosts is vCenter Server. This management tool is essential for operating a virtualized environment effectively. It enables the centralized administration of ESXi hosts and the virtual machines running on them.

By utilizing vCenter Server, administrators can perform tasks such as resource allocation, load balancing, and automated VM deployment across different physical hosts. This enhances efficiency and improves resource utilization in a virtualized environment, allowing for features like Distributed Resource Scheduler (DRS), High Availability (HA), and vMotion, which all require management capabilities provided by vCenter.

In contrast, the VMware vSphere Client is primarily a user interface for managing the environment but does not itself manage resources across multiple hosts. VMware ESXi is the hypervisor that runs the virtual machines on individual hosts but does not provide management capabilities for multiple hosts. Virtual Machine Manager, while similar in function, is not the standard term used in the VMware context and typically refers more to a feature of a specific product rather than a core component of the vSphere suite.