NetBoot was a technology from Apple which enabled Macs with capable firmware (i.e. New World ROM) to boot from a network, rather than a local hard disk or optical disc drive.

[1] NetBoot has continued to be a core systems management technology for Apple,[2] and has been adapted to support modern Mac Intel machines.

Clients receive this image across a network using many popular protocols including: HTTPS, AFP, TFTP, NFS, and multicast Apple Software Restore (ASR).

NetInstall is a similar feature of macOS Server which utilizes NetBoot and ASR to deliver installation images to network clients (typically on first boot).

NetInstall performs a function for macOS similar to Windows Deployment Services for Microsoft clients, which depend on the Preboot Execution Environment.