VMware vSphere, also referred to as ESXi or even ESX for earlier versions, is a Type 1 hypervisor that is the virtualization platform used for the vSphere suite of products. Type 1 hypervisors are designed to run directly on the host hardware, whereas Type 2 hypervisors run within a conventional OS environment.

ESXi is the only hypervisor that is fully supported by VMware for hosting Horizon virtual desktops, as it fully integrates with Horizon for full desktop life cycle management. All of the primary desktop provisioning and maintenance tasks are performed using the Horizon Administrator console; the vSphere Client is not used. Horizon supports multiple versions of vSphere, but vSphere 6.0 Update 1 and newer are required to leverage many of the latest features of the platform. vSphere 6.0 Update 2 or newer is required to use the latest version of Virtual SAN (vSAN). Refer to the VMware vCenter Server requirements section for examples of some Horizon features that require a specific version of both vSphere and vCenter Server.

VMware vSphere also includes the vSAN feature that uses local ESXi server storage to build a highly resilient virtual Storage Area Network (SAN) to provide storage for virtual machines. The deployment and configuration of vSAN are outside of our scope, so consult the Horizon documentation (https://docs.vmware.com/en/VMware-Horizon-7/index.html) if you require information about using vSAN with Horizon.