Creating a bootable USB drive let's you get hands-on experience with Linux without necessarily overwriting your system.

Perhaps they referenced this guide to create a bootable Live USB on Windows, allowing them to test drive something like Ubuntu without making any changes to their PC.

How to make a bootable USB drive If you're trying to install a new operating system or flash your BIOS, you're going to need a bootable USB drive - here's how to make one.

Once you’ve got it burned to CD, boot your PC with that CD in the drive, wait a few minutes, and you’ll be booted into Umbuntu Linux. Then select System • Administration • Create a USB ...

Trying to get started with VMware's virtualization app but lack an optical drive on your Apple computer? Here's how to transform the ISO into a bootable flash drive for installing the hypervisor.