possibility of transferring the system in a USB Hard Disk

[the_bertrum]

perhaps @cofot28  believes that  install always happens from sd card ? and is unaware that the downloaded image can be written to sd-card or usb stick or ssd and the Pi booted from any of those for install and subsequent use.?

I must say, it's the first time I can recall that being said in such clear and unambiguous terms.  Are there any steps lurking in the "and the Pi booted from any of those" part.