It’s important to understand what kind of floor you are choosing before it is put in.
A “floating floor” means that the pieces of the floor interlock with each other. They aren’t attached to the sub-floor, but rather “float” on top of it.
A floor that is glued down has been attached to the sub-floor with an adhesive.
A nailed-down floor needs to have plywood or the like underneath to be nailed to. Both this and the glued-down floor create a floor that feels sturdier, since they are secured to sub-floors.