Well...the British use ceiling boxes just like we do for those regular up against the ceiling fixtures, i think. Except that I believe the fixtures sometimes have an integrated connector block, right Paul? Or is the connector block a part of the ceiling box?
This fixture is sold through one certain British electrical supply house:
The version sold in the States comes with pigtails coming out the top that get spliced into the wires in the box. Then machine-bolts passed through holes the tin canopy (that holds the lampholder) screw into threaded tabs in the ceiling box.
You certainly need a box for this most basic of fixtures:
A long time back they used to sell shades that would clip to this sort of lampholder itself. I haven't seen these anywhere now. The only thing I've seen for them are those yellow plastic bulb cages (and the wire versions).
Now they sell also these cheesy things that have a spring-action clip that grabs the bulb itself.
Some chandeliers and ceiling fans hand from fan-rated ceiling box. These use a horizontal brace that attaches between two joists so it's stronger than a regular box with a bracket.
"Swag" lamps hang from a chain onto a hook and then the connections are made to a nearby ceiling box (covered by a tin canopy). I believe the same applies for heavy chandeliers.
One thing we don't have, that I LOVE are these cheezy things that you can attach these paper shades to:
Of course I could make one myself using a ceiling canopy, strain relief & cord grip bushing, stump of flex and a lampholder scrapped from a table lamp.
Behold the finished product:
Sorry for all the pix.