The days of having to wax and scrub your hardwood floors are pretty much gone forever. Manufacturers of prefinished wood floors have developed sophisticated techniques to quickly apply hard, durable, urethane based finishes right at the factory. By using ultra violet lights the prefinished wood planks can have several coats of urethane applied within a matter of a few minutes. This is helping make hardwood floors both more affordable, and much easier to maintain. Recently, the hardwood flooring manufacturers have begun to add small chips of Aluminum Oxide directly to the floor's finish which dramatically increases the life of the urethane finish.
Most factory finished hardwood floors have several coats of finish applied to the wood's surface. As example, many wood floor companies are applying 6-10 coats of a ultra-violet (UV) cured urethane. This would be extremely difficult for someone to duplicate on a job site finish, not to mention how many days it would take. This is one of the reasons why many flooring mechanics, flooring retailers, and builders are pushing prefinished hardwood floors. Instead of taking several days to install and finish a new hardwood floor a prefinished hardwood floor is generally done in one day.
This does not mean you should wash your floor with a mop, but it does mean these floors won't watermark like the old waxed hardwood floors. The the UV cured urethane wood finishes do make these floors easier to maintain than the old waxed hardwood floors.
Wood floors that have been factory finished before they are installed.
If you want a custom stained hardwood floor, or a wood floor to match existing trim than a job-site finish is your answer. Job-site finish means you start with a bare (unfinished) hardwood floor and than the floor is sanded, stained, and finished in the home. The other advantage of a job-site finish is if you are concerned with uneven heights between planks, the sanding process will smooth out the floor. Be warned, this can be quite a mess and the process does take several days.