An introduction to the components and features of VMware vSphere helps you to understand the parts and how they interact.

VMware vSphere includes the following components and features.

VMware ESXi

A virtualization layer run on physical servers that abstracts processor, memory, storage, and resources into multiple virtual machines.

VMware vCenter Server

The central point for configuring, provisioning, and managing virtualized IT environments. It provides essential datacenter services such as access control, performance monitoring, and alarm management.

VMware vSphere Client

An interface that enables users to connect remotely to vCenter Server or ESXi from any Windows PC.

VMware vSphere Web Client

A Web interface that enables users to connect remotely to vCenter Server from a variety of Web browsers and operating systems.

VMware vSphere SDKs

Feature that provides standard interfaces for VMware and third-party solutions to access VMware vSphere.

vSphere Virtual Machine File System (VMFS)

A high performance cluster file system for ESXi virtual machines.

vSphere Virtual SMP

Enables a single virtual machine to use multiple physical processors simultaneously.

vSphere vMotion

Enables the migration of powered-on virtual machines from one physical server to another with zero down time, continuous service availability, and complete transaction integrity.

Migration with vMotion cannot be used to move virtual machines from one datacenter to another.

vSphere Storage vMotion

Enables the migration of virtual machine files from one datastore to another without service interruption. You can place the virtual machine and all its disks in a single location, or select separate locations for the virtual machine configuration file and each virtual disk. The virtual machine remains on the same host during Storage vMotion.

Migration with Storage vMotion lets you move the virtual disks or configuration file of a virtual machine to a new datastore while the virtual machine is running. Migration with Storage vMotion enables you to move a virtual machine's storage without any interruption in the availability of the virtual machine.

vSphere High Availability (HA)

A feature that provides high availability for virtual machines. If a server fails, affected virtual machines are restarted on other available servers that have spare capacity.

vSphere Distributed Resource Scheduler (DRS)

Allocates and balances computing capacity dynamically across collections of hardware resources for virtual machines. This feature includes distributed power management (DPM) capabilities that enable a datacenter to significantly reduce its power consumption.

vSphere Storage DRS

Allocates and balances storage capacity and I/O dynamically across collections of datastores. This feature includes management capabilities that minimize the risk of running out of space and the risk of I/O bottlenecks slowing the performance of virtual machines.

vSphere Fault Tolerance

Provides continuous availability by protecting a virtual machine with a copy. When this feature is enabled for a virtual machine, a secondary copy of the original, or primary, virtual machine is created. All actions completed on the primary virtual machine are also applied to the secondary virtual machine. If the primary virtual machine becomes unavailable, the secondary machine becomes immediately active.

vSphere Distributed Switch (VDS)

A virtual switch that can span multiple ESXi hosts, enabling significant reduction of on-going network maintenance activities and increasing network capacity. This increased efficiency enables virtual machines to maintain consistent network configuration as they migrate across multiple hosts.

Host Profiles

A feature that simplifies host configuration management through user-defined configuration policies. The host profile policies capture the blueprint of a known, validated host configuration and use this configuration to configure networking, storage, security, and other settings across multiple hosts. The host profile policies also monitor compliance to standard host configuration settings across the datacenter. Host profiles reduce the manual steps that are involved in configuring a host and can help maintain consistency and correctness across the datacenter.

Host profiles are also a component of vSphere Auto Deploy. The concept of an autodeployed host means that vCenter Server owns the entire host configuration and it is captured within a host profile. Certain policies require user input to provide host-specific values. To support Auto Deploy for host profiles, an answer file is created that contains the definitions for those policies.