Fender refers to a part that covers the front wheels to prevent mud splattering.
The fender's opening for the wheels' well tend to be larger than the diameter of the tire, because they do not move with the tire suspension and must be larger enough to allow the full range of tire motion on the suspension without touching the interior of the wheel well.
An aftermarket accessory is available such as fender flares, which block mud and stones and cover rust. They are sometimes used by manufacturers on models that have wider tires than basic models. Using this way, the manufacturers can provide the needed tire coverage without producing a different fender, bed side or quarter panel that may be a low production model
Fender skirts are implemented for aesthetic and aerodynamic functions. Instead of air flowing into and being trapped in the rear wheel well, it flows smoothly over the bodywork.
They are generally detachable to allow for tire changes and installation of snow chains
These devices are fitted on the body, close to the wheels; As the vehicle approached the curb, the protruding feelers works to scrape against the curb, making a noise, and alerting the driver in time to avoid wheel damage.