DE is for “Desktop environment”. Most distro let you choose from quite a few. The two best known one are Gnome and KDE, i believe. But there are many more.

“Desktop environment” might just be two words without much meaning to you. If that the case, in the linux context, a desktop environment is basically the GUI to your computer: file explorer, desktop, taskbar, general setting manager and so on.

The electrical code in my area requires using GFCI outlet for outlets within a certain distance of water source. I don’t remember precisely the distance (and it likely vary a bit by jurisdiciton), but i know that in my bathroom, there’s nowhere beyond it.

In order to use that sort of outlet in a bathroom like mine, it would have to have GFCI protection as well as USB, be a second outlet wired to the GFCI protected terminal of a GFCI outlet, or be wired to a circuit breaker with GFCI protection built in, in the electrical panel.