vSphere Auto Deploy lets you provision hundreds of physical hosts with ESXi software.
Using Auto Deploy, experienced system administrators can manage large deployments efficiently. Auto Deploy can be used for stateless caching or stateful installs.
Auto Deploy requires a secure separation between the production network and the management or deployment networks as discussed in Auto Deploy Security Considerations. Using Auto Deploy without this separation is insecure.
By default, Auto Deploy does not store ESXi configuration or state on the host disk. Instead, an image profile defines the image that the host is provisioned with, and other host attributes are managed through host profiles.
You can provision a host with Auto Deploy and set up the host to store the image to disk. On subsequent boots, the host boots from disk.