A windsock, also sometimes called a wind cone, is a fabric tube that is set up to flutter in the wind. It is generally attached at one end to the top of a pole so that it waves in the wind, like a flag, but can be attached to any type of metal frame or a stable object that is projected out of the ground or a building.
A windsock's purpose is to indicate which way the wind is blowing, and indicate wind speed. A windsock that points north is revealing that the wind is coming from the south.
Windsocks are used at homes, farms, schools and businesses. Windsocks are also commonly used for advertising and promotion. They are often found at airports and chemical plants, where there is always a risk of a hazardous gas leakage, and along highways in windy locations.
Windsock designs are virtually unlimited. They are typically sewn together, and can incorporate elements of a flag, a sports team or business logo, animal designs or other patterns.
According to BasicWindsocks.com, the windsock was invented by the Japanese hundreds of years ago. The Japanese would fly them on "Boys Day" to celebrate a family's male offspring. They would mount the windsocks on top of bamboo poles so they would blow in the wind. One windsock would represent one son. Windsocks were in the shape of a carp (fish), and were embossed with the family crest.