The vSphere Client is an application that enables management of a vSphere installation. The VMware vSphere Client is a web-based application that connects to the vCenter Server so. The vSphere Client is an interface for administering vCenter Server and ESXi. vSphere Client is a Windows-only application that allow you to connect directly to an ESXi host or to a vCenter Server instance. vSphere Web Client is a cross-platform web application that enables you to connect to a vCenter Server system to manage ESXi hosts.