Human hair was hair that grew on a person's body.

It could be used as a potion ingredient.

During her sixth year, Hermione Granger used her own hair as an ingredient in an antidote that she brewed in Potions class.

It was also commonly used in the Polyjuice Potion as the part of the person one wished to turn into.

Vincent Crabbe's and Gregory Goyle's hair was used by Ron Weasley and Harry Potter.

The hair of Harry Potter was used for the Polyjuice transformation during the Battle of the Seven Potters.

The hair of a red-haired Muggle boy was used during the wedding of William Weasley and Fleur Delacour.

Hermione Granger used Bellatrix Lestrange's hair for her Polyjuice tranformation in 1998.

There were spells that made an individual lose its head hair or make it thicker.

An individual's hair colour and style could be changed with complex human transfiguration spells.

A Metamorphmagus could change his or her hair just by concentrating.