Floor Coverings and finishes protect both the people on top of the floors and the structure underneath them by providing a walkable surface.

Immediately beneath the floor covering is the "subfloor," this is the structural element that supports the flooring. In some cases, buildings may have floating floors, raised floors or sprung floors that are above the subfloor - but all buildings have a subfloor. Some of them might be underground ("below grade,") and will typically have a concrete floor. Others that are above ground ("above grade,") usually have a plywood subfloor. Determining what your subfloor is constructed of is an important step to take before choosing your floor covering.

Additional qualities of flooring materials to consider include price point, longevity, acoustical properties, style, comfort and car & maintenance requirements.

Different types of flooring materials serve different purposes:

Carpet
softens a space and is quick and inexpensive.
Hardwood
is a natural look that adds value while providing design and function.
Tile
is eco-friendly, hypoallergenic and long-lasting.
Luxury Vinyl Plank
is resilient, kind to feet and great for pets.
Linoleum
goes in fast and adds comfort underfoot.
...every flooring material out that has a unique set of characteristics that sets it apart. Additional features can add additional benefits. 

"There are a number of special features that may be used to ornament a floor or perform a useful service:

Floor medallions decorative centerpieces of a floor design
Doormats to help keep a floor clean
Gratings used to drain water or to rub dirt off shoes
Tactile or rumble strips to warn of for instance a wheelchair ramp, these would normally also be distinctively colored or patterned.

Light strips to show an escape route out, especially on airplanes.
Moldings or baseboards to decorate the sides of a floor or to cover the edge of a floating floor.
Anti-slip mats: The addition of either granular or rubberized particles that will allow wheels, shoes, or feet better traction."  (wikipedia: flooring)