Floating floor planks. Generally wood laminate / artificial planks that sit on top of existing flooring or subfloor, and generally click together at the sides and ends. They’re pretty common for newer homes and for cheaper floor replacements.

They’re not a bad option. They’re cheap and benefit from individual planks being relatively easy to replace if damaged, but the drawback is they tend to shrink and expand a bit and can shift with temperature and humidity fluctuations.

I have floating floor in my home and every few months as the temp and humidity changes occur with the seasons have to use a suction gripper and mallet to knock closed gaps in a few places where they can shift anywhere from 1/16 to up to 1/4 inch if/where the ends have separated in places. But it means caulking under the toilet was a bad move because they’re designed to be able to shift slightly, and sealing them down that way can cause issues and eventually the seal will break from the pressure of the planks shifting. And doing it caused a few gaps to form where there were none previously.

I’m not a big fan of this flooring application, and am considering going with glue down engineered wood in the future when it needs replacing.