Here is a condensed version of the Terminal commands required to convert the installer to an ISO:
After updating, you can create a new ISO of the updated system using the same Terminal commands above. Keep both a "base ISO" and an "Updated 10.13.6 ISO" on your backup drive.
: This is commonly used for installing macOS in VirtualBox or VMware . Scripts like gibMacOS can automate the process of building the installer from Apple's servers.
It is the last version to support 32-bit applications, making it essential for legacy software. However, many modern apps (like latest Adobe or Chrome versions) no longer support it. Security
Place Install macOS High Sierra.app in your /Applications folder.