What is the introduction of folk songs?

Folk songs are the unified names for such traditional folk songs by scholars or academic circles. In fact, the names of folk songs are different in different regions and ethnic groups, such as "Huaer" in Qinghai, Gansu and Ningxia, "Qu Shan" in Shanxi, "Journey to Heaven" in Shaanxi, "Mountaineering Tune" in Inner Mongolia and "Mountaineering Tune" in eastern Sichuan. These folk appellations are often associated with profound social and historical background, or imply some rich and profound folk cultural connotations, which deserve our attention.