The word “piercing” has occurred from English “pierce”- to pierce, to bore through. Honestly speaking, piercing is understood as threading subjects in the apertures made with this purpose on a body or the person. The same name has also the subject entered into the made aperture, for example a ring.
Now piercing carries out decorating, erotic and other functions. The most popular places for piercing are: ears, belly-button, eyebrows, lips, wings of a nose, genitals, dummies, language.
Piercing procedure is quite simple: in any part of a body the aperture is pierced, then the subject is passed in it. It can be in the form of a tree, an ivory, metal, plastic, etc. Or it is pierced with a small core on which pearl, brilliants, amber are fastened.
The most widespread form of piercing is ear rings in pierced female ears. Ornaments in them are summarized more often on both ears, but nowadays the asymmetry is more preferable.  
Modern piercing of the ears became much more various - from a puncture of the ear lobule up to a set of ear rings in a cartilage. Ears piercing heal for a long time. If it is a puncture of the ear lobules - the healing will take 3-4 months and if the puncture has been made in a cartilage, the healing will take almost half a year.  
Piercing of the ears is a traditional procedure, and erotic piercing is an absolutely new kind of the piercing, which receives the increasing popularity.