Microdermabrasion
Microdermabrasion is, literally, a form of sandblasting the skin to remove the surface cells.
Originally inert crystals were used, followed by salt. Nowadays the salt has been done away with altogether and a rotating crystal is used instead. This eliminates the risk of contamination (some salons were reusing the old salt or crystals!) but it is still a very intense treatment.
Not everyone will find this a good treatment, and it’s probably not a good idea to have it on a regular basis. However it is good for buffing the skin when the weather changes, and can be useful for removing light pigmentation marks.