There are four different ways to install hardwood flooring:
Locking or Floating
This is an excellent do-it-yourself product because nails, staples and glue aren't required. All you have to do is roll out the moisture barrier underlayment for moisture protection, and then float the floor over the subfloor by locking the planks together. This type of installation offers the added advantage of allowing the flooring to better expand and contract with humidity.
Gluing involves troweling glue on the floor and setting the planks into the glue. Adhesive systems that incorporate a moisture barrier to help mitigate moisture-related issues are available.
Nailing involves driving a nail at an angle through the tongue of the hardwood floor into the wood subfloor. The nail is then hidden by the groove of the next row of boards.
This is similar to the nailing process but with staples.