Good post by Rawlinson Rivera (thank you)
In 2011 VMware introduced block based VAAI APIs as part of vSphere 4.1 release. This APIs helped improving performance of VMFS by providing offload of some of the heavy operations to the storage array. In subsequent release, VMware added VAAI APIs for NAS, thin provisioning, and T10 command support for Block VAAI APIs.
Now with Virtual Volumes (VVOLs) VMware is introducing a new virtual machine management and integration framework that exposes virtual disks as the primary unit of data management for storage arrays. This new framework enables array-based operations at the virtual disk level that can be precisely aligned to application boundaries with the capability of providing a policy-based management approach per virtual machine.
Read on here