You have several ways to access vSphere components through vSphere interface options.
vSphere interface options include:
vSphere Web Client
The vSphere Web Client is a Web application installed on a machine with network access to your vCenter Server installation. The vSphere Web Client is the primary interface for connecting to and managing vCenter Server instances.
vSphere Command-Line Interface
A command-line interface for configuring an ESXi host.
See Starting and Stopping the vSphere Components for information and instructions about starting and stopping ESXi hosts and vCenter Server.