Threading is a method of hair removal originating in Asia. In more recent times it has gained popularity in Western countries, especially with a cosmetic application (particularly for removing/shaping eyebrows).
In threading, a thin (cotton or polyester) thread is doubled, then twisted. It is then rolled over areas of unwanted hair, plucking the hair at the follicle level. Unlike tweezing, where single hairs are pulled out one at a time, threading can remove short rows of hair.