If you have more than one Mac you want to upgrade to macOS 10.15 Catalina but don't want to waste so much bandwidth downloading it for each machine, one option is to create a bootable installer on ...

How to make your own bootable OS X 10.9 Mavericks USB install drive Apple has changed things in 10.9, but making a recovery drive is still possible.

To turn a standard USB drive into an installation drive, you'll need to use a program called Rufus. It's the same app that Microsoft itself uses in its guide for creating a Windows 10 bootable drive.

How to create a macOS Monterey USB Install drive for quick and easy installations of Apple's latest operating system for Mac.