Running Ubuntu directly from either a USB stick or a DVD is a quick and easy way to experience how Ubuntu works for you, and how it works with your hardware.
How to write a USB stick with Windows. Alternatively, we also have tutorials to help you create a bootable USB stick from both Ubuntu and Apple macOS.
A Linux live USB drive is normally a blank slate each time you boot it. if you're just using a USB drive to install Ubuntu and then running it.