Official versions of macOS High Sierra 10.13.6 are not natively distributed as ISO files by Apple. Instead, Apple provides the software as an installer app through the Mac App Store or as a disk image (.dmg) on their support pages.

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/HighSierra --nointeraction

• macOS High Sierra (10.13): Released in September 2017, it introduced the Apple File System (APFS), HEVC (High Efficiency Video Coding) support, and Metal 2 graphics technology.
• Version 10.13.6: Released in July 2018, this was the final "gold master" update. It added support for AirPlay 2 and resolved dozens of bugs. For IT administrators, it is the most stable and secure version of High Sierra.
• ISO vs. DMG: A .dmg file is Apple’s native disk image format. An .iso is a universal disk image format used globally, especially for virtual machines (VMware, VirtualBox, Parallels). When people search for an "ISO download," they typically want a bootable file that works on both Mac hardware and PC-based hypervisors.

Furthermore, the 10.13.6 ISO is a crucial tool for legacy hardware support. As Apple continues to release new versions of macOS, older Mac models are often cut off from support. High Sierra is the last supported operating system for several mid-2010 and late-2011 iMacs and MacBook Pros. For owners of these machines, obtaining a clean installation file is necessary for wiping and restoring a device. While Apple allows installing from a bootable USB, the ISO format provides a versatile backup that can be stored on a server, ensuring that the ability to reinstall the OS is never lost to time or removed links.

Convert to ISO: hdiutil detach /Volumes/Install\ macOS\ High\ Sierra and then hdiutil convert /tmp/HighSierra.dmg -format UDTO -o ~/Desktop/HighSierra.iso Alternative Tools Mac OS High Sierra 10.13 iso : Apple - Internet Archive

. Note that this link often only opens correctly if you are on a Mac that is compatible with High Sierra. Direct Link (DMG): If the App Store doesn't work, Apple provides direct DMG downloads for older macOS versions on their support site. 2. Create the ISO (The "Piece" You Need) Since you specifically asked for an

1. Get the official installer from Apple’s support page.
2. Create your own ISO using the terminal method above.
3. Use it only on hardware or VMs you own.