Nail or Staple
This is the conventional installation method for hardwood floors. Most solid hardwood flooring must be installed this way, but is optional for many engineered hardwood products. Whether to choose nails or staples can depend on the product, the substrate (the surface you are going over) or both. Be sure to read the installation instructions before proceeding and contact your retailer for any additional details.

Glue
Used most often to install engineered hardwood where nailing is not possible (on concrete for example)

Float
This method assembles the flooring to itself piece by piece, separated from the substrate by an underlayment. It can be either glued together or with the advent of integrated locking systems, “clicked” together. The floor “floats” over the substrate so it can be installed over any sound, flat surface; even existing floorcoverings!