Flash drive Saving from android phone and laptop? - using Dual-Drive C and A usbs

Long ago, looked into the photo saving commercial device specifically for that, then saw on the internet that it wasn't that secure or long lasting.

So what about flash drives. Are they long lasting, probably not "permanent"? Do flash need programming?

I guess the steps are probably available to be found, the mechanics. But

*** So, let's say that the pics on the android phone have been moved onto the flash and they have been erased off the phone or laptop: Seems like it would be a hassle when Attaching a pic to an email and such, have to plug in the flash to find it? Carry it around somewhere on a key chain?

Have had three flash drives unopened for over a year, procrastinating about messing around. I don't know exactly what I'm asking here, any guidance, including step by step mechanics, will be appreciated.