How to create a bootable installer for macOS

I had to reinstall macOS to my mac mini, because I replaced HDD in my mac mini. I tried to reinstall macOS via the internet, but I could not, because of the limited bandwidth of my internet connection. Then I used the USB-installer.

The step of making USB-installer is described at the following WWW page.

How to create a bootable installer for macOS
https://support.apple.com/en-us/HT201372

The steps are the following:

1. Download macOS from the App Store. When the macOS installer opens, quit it without continuing installation.
2. Connect your Mac to the USB flash drive or other volume that will be used as the bootable installer. Make sure that it has at least 12GB of available storage.
3. Execute the following commands in Terminal(This example is for High Sierra).

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