Creating a bootable installer for macOS is an essential skill for any Apple Systems Engineer. A bootable installer allows you to install macOS on multiple computers without needing to download the installer each time. This can save significant time and bandwidth, especially in environments where multiple systems need to be set up or reinstalled. In this article, we will cover the steps required to create a bootable installer for macOS using the Terminal application.

Examples:

1. Download the macOS Installer: First, you need to download the macOS installer from the App Store. For instance, to download macOS Monterey, open the App Store, search for "macOS Monterey," and click the download button. The installer will be saved in the Applications folder.

2. Prepare a USB Drive: Insert a USB drive with at least 16GB of storage into your Mac. Make sure to back up any important data on the USB drive, as it will be erased during this process.

3. Format the USB Drive: Open Disk Utility (found in Applications > Utilities), select your USB drive from the list, and click "Erase." Choose "Mac OS Extended (Journaled)" as the format and "GUID Partition Map" as the scheme. Name the drive something like "MyVolume" and click "Erase."

4. Create the Bootable Installer: Open Terminal (found in Applications > Utilities) and enter the following command, replacing "Monterey" with the appropriate macOS version if necessary:

   sudo /Applications/Install\ macOS\ Monterey.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

   You will be prompted to enter your administrator password. After entering the password, the Terminal will guide you through the process of creating the bootable installer. This may take some time, so be patient.

5. Boot from the Installer: Once the process is complete, you can boot any Mac from the USB drive. To do this, restart the Mac and hold down the Option (⌥) key while it boots up. Select the USB drive from the list of bootable devices to start the macOS installation process.