Practicals

Any aspect of a set that works as in real life onstage is called "practical."

Doors and windows of a set can be mere illusion or "practical."  So can be any new-built cabinet door or drawer: it's "practical" if it actually opens and has insides to it, but many such cabinetry pieces are dummies  because that's cheaper and easier to build.  Any sink that runs water is "practical" (as in The Beauty Queen of Leenane) as would be any telephone, radio, TV, or other appliance that actually operates, rather than being faked.

A Bright New Boise will have practical cabinets, a sink, a microwave (well, maybe), and a Coke machine.

This will be "practical."  It'll spit Cokes.  But we're going to unscrew its light bulbs so it won't glow during blackouts.

ADDENDUM:  Well... maybe it won't be practical.  There's some concern about the hum of its compressor!