To make a ponytail, some, most or all of the hair on the head is pulled away from the face, gathered and secured at the back of the head with a hair tie, clip, or other similar device and allowed to hang freely from that point. It gets its name from its resemblance to the undocked tail of a horse or pony. Ponytails are most commonly gathered at the middle of the back of the head, or the base of the neck. Depending on fashions, they may also be worn at the side of the head (which is sometimes considered formal) which is worn over one ear, or on the very top of the head (allowing the hair to fall down the back or one side of the head).
If the hair is divided so that it hangs in two sections they are called "ponytails" or pigtails (or bunches), if left loose, and pigtails, plaits or braids if plaited. Unbraided ponytails worn above each ear are sometimes called dog-ears.
It is common for those who wear tight ponytails to experience traction alopecia, a form of hair loss. Sometimes it can cause a headache.
Women (as opposed to girls) complying with European fashion of the Georgian period and to the 20th century rarely were seen outside of the boudoir with their hair in such an informal style as a ponytail.
Today, both women and girls commonly wear their hair in ponytails in informal and office settings or when exercising; they are likely to choose more-elaborate styles (such as braids and those involving accessories) for formal occasions. It is a practical choice as it keeps hair out of the eyes. It will keep the hair off the neck as well. The ponytail is also popular with school-aged girls, partly because flowing hair is often associated with youth and because of its simplicity; a young girl is likely to be able to retie her own hair after a sports class, for example. A ponytail can also be a fashion statement; sometimes meaning sporty, other times a low pony tail sends signals of a chic personality.
In the late 18th century, men often tied their ponytails with a black ribbon.
In the 1970s, many men wore their hair long and in ponytails. This look was popularized by 1970s-era rock musicians.
In the late 1980s, a short ponytail was seen as an impudent, edgy look for men who wanted to individualize, but keep their hair flat and functional (see mullet). Steven Seagal's ponytail in Marked for Death is an example of such.