The carol (villancico), as its name indicates, is the village song; that one to served to record the daily life of the towns. According to some historians, this songs emerged in the 13th century, being spread in Spain in the 15th and 16th centuries, and in Latin America since the 17th century. In its beginnings it was a  Spanish poetic form and they used it as a record of the main events of a region. Source.