Backup data to an usb device

[habicht]

It is possible to backup data to an usb device, e.g. usb disk?

I want to backup data from an users home. So only a part
of a filesystem.

[Al-S]

Yes you can backup your data to a USB disk, or an external HDD that connected through USB.
but in general USB flash memory is not very trusted to keep your important data on it, or to use if for a very long time.