What is the meaning of the ends of the earth in singing and smiling?

Take smiles and songs to distant places. Singing Smile is a song written by Wang Jian, composed by Gu Jianfen and sung by Shanghai Xiaoying Star Children's Choir. "Tianya Haijiao" in the lyrics refers to bringing smiles and songs to distant and distant places. Singing and smiling were posted on 1986. 1989, the song entered the stage of CCTV Spring Festival Evening, and won the Excellence Award of China Campus Song Creation Grand Prix in the same year.