Probably double-sided prototyping PCBs. The double-sided ones tend to be green (FR4 fiberglass resin), the single-sided orange (FR2 paper phenolic-resin).

Terminology varies, a lot of greymarket sellers use “veroboard”, “prototype board” and “breadboard” interchangeably.

The glue between the copper pads and the board itself tend to better with the double-sided boards, I agree with you OP :) Although this isn’t universal, I’ve had some nasty bare copper boards on FR4 where the pads pop off when you try to solder to them; and some old FR2 boards with really well adhered pads. I’ve read somewhere that this might (?) be due to moisture in the PCB boiling off when you put the soldering iron to a pad and that baking the board in an oven first can help, but I have not tried that. I suspect a lot of it comes down to the quality of adhesive used between copper and substrate.