This tutorial aims at showing a fast, straightforward way of creating a USB flash drive with Debian live installed (on it) using the persistence feature. It means that you can automatically save changes back to the USB flash drive before shutting your machine down.There are many more options not covered in this article which are explained in detail in Debian-live's manual
linux com/community/blogs/133-general-linux/420179-creating-a-debian-live-usb-flash-drive-with-persistence-for-non-techies