Bootable USB
I am not sure what to call this subject. Clearly, we are talking about Linux rather than Windows for the most part.
Maybe this page should be called PortableLinuxOperatingSystems ... the basic idea is that the operating system is entirely portable and can be booted on a wide range of machines, not just one machine. This makes multi-machine configurations very flexible and adaptable to a given usage scenario.
Wikipedia calls it "Live USB", although my interest is mostly booting from USB Flash Drives rather than USB Disk Drives.
https://en.wikipedia.org/wiki/Live_USB
A live USB is a USB flash drive or a USB external hard disk drive containing a full operating system that can be booted. Live USBs are closely related to live CDs, but sometimes have the ability to persistently save settings and permanently install software packages back onto the USB device.
Like live CDs, live USBs can be used in embedded systems for system administration, data recovery, or the testing of operating system distributions without committing to a permanent installation on the local hard disk drive ...
... A user can carry his or her preferred operating system, applications, configuration, and personal files with them, making it easy to share a single system between multiple users.
https://en.wikipedia.org/wiki/Category:Live_USB
https://en.wikipedia.org/wiki/Category:Operating_system_distributions_bootable_from_external_media
Related to https://en.wikipedia.org/wiki/Portable_application
A portable application (portable app), sometimes also called standalone, is a program designed to run on a compatible computer without being installed in a way that modifies the computer's configuration information.
This type of application can be stored on any storage device, including internal mass storage and external storage such as USB drives and floppy disks – storing its program files and any configuration information and data on the storage medium alone.
https://en.wikipedia.org/wiki/Windows_To_Go
Windows To Go is a feature in Windows 8 Enterprise, Windows 10 Enterprise, and Windows 10 Education that allows them to boot and run from USB mass storage devices such as USB flash drives and external hard disk drives. It is a fully manageable corporate Windows environment.
Not sure why a home or small business user would want to, but it can be done ... far more likely to be a Windows user in need of Linux functionality.
http://www.pendrivelinux.com/
See Linux#PuppyLinux
