With the floating installation method the floor is not mechanically fastened to any part of the subfloor.
A thin pad is placed between the wood flooring and the subfloor. Then a recommended wood glue is applied in the tongue and groove of each plank to hold the planks together.
The padding has its advantages: it protects against moisture, reduces noise transmission, is softer under foot, and provides for some additional "R" value.
Some engineered floors and all Longstrip floors can be floated. This is a very fast, easy and clean method of installing your floor.