Silk is an animal fibre produced by certain insects and arachnids as building material for cocoons and webs, some of which can be used to make fine fabrics. In commercial use, silk is almost entirely limited to filaments from the cocoons of domesticated silkworms. The origin of silk production and weaving is ancient and clouded in legend. The industry undoubtedly began in China, where, according to native records, it existed from sometime before the middle of the 3rd millennium BCE.

Source: Britannica