More than just characteristics
Plush or Saxony Plush or Textured Cut Pile
Today any carpet with less texture than a frieze or twist carpet are generically termed Textured Cut Pile carpets. A cut pile carpet with a smooth and lustrous finish (surface) may be called a Plush or Saxony Plush and if the carpet is also dense and lustrous, it may be called a Velvet. These terms used less often today but are still useful. This type of carpet will show more footprints, vacuum tracks, and shading due to the uniform finish.
Twist - Heavily Textured
Usually indicates more crimping or bending in the yarns resulting in much more texture than a Cut Pile Plush. Depending on how tall the yarns are and how close the yarns are tufted together, the appearance can vary from a shaggy look to a denser look but still textured appearance. In general, carpets with more texture show less foot printing, shading, and vacuum tracking than plush or Saxony plush.
Loop Pile Carpet
When used in residential applications, loop pile carpets are often called Berber carpet. The loops can be of equal height (level loop) or multi-level. Multi-level loops can be tufted to form patterns and flecks of color may also be incorporated. Since there are no cut yarn tips to untwist and tangle, loop pile carpets are considered more resistant to abrasive wear. Unlike cut pile carpets, loop carpets, if snagged can run as one loop is connected to the next.
Originally the term frieze indicated a cut pile carpet that derived it's texture (bent or curly yarns) from extreme twisting of the yarns. Today any carpet that has an above average twist rate and looks textured is likely to be a frieze, even if the texture is derived from mechanically crimping or bending the yarns. These carpets show less shading and foot printing compared to plush cut pile carpets. Frieze carpets offer excellent durability and ease of maintenance.