The main components of ESX/ESXi include a virtualization layer, hardware interface components, and user interface.

An ESX/ESXi system has the following key components.

Virtualization layer

This layer provides the idealized hardware environment and virtualization of underlying physical resources to the virtual machines. This layer includes the virtual machine monitor (VMM), which is responsible for virtualization, and the VMkernel. The VMkernel manages most of the physical resources on the hardware, including memory, physical processors, storage, and networking controllers.

The virtualization layer schedules the virtual machine operating systems and, if you are running an ESX host, the service console. The virtualization layer manages how the operating systems access physical resources. The VMkernel must have its own drivers to provide access to the physical devices.

Hardware interface components

The virtual machine communicates with hardware such as CPU or disk by using hardware interface components. These components include device drivers, which enable hardware-specific service delivery while hiding hardware differences from other parts of the system.

User interface

Administrators can view and manage ESX/ESXi hosts and virtual machines in several ways:

A VMware vSphere Client (vSphere Client) can connect directly to the ESX/ESXi host. This setup is appropriate if your environment has only one host.

A vSphere Client can also connect to vCenter Server and interact with all ESX/ESXi hosts that vCenter Server manages.

The vSphere Web Access Client allows you to perform a number of management tasks by using a browser-based interface.

When you must have command-line access, you can use the VMware vSphere Command-Line Interface (vSphere CLI).