The difference between marriage alliance and marriage lies in their different expressions and origins.
Expressing different meanings
1. Joint marriage: entering into a marital relationship; Family members and friends of both men and women are drinking a wedding banquet at the same time.
2. Marriage: refers to a civil legal act in which both spouses establish their marital relationship in accordance with the conditions and procedures prescribed by law, and assume the rights, obligations, and other responsibilities arising therefrom.
Different sources
1. Joint marriage: from the autobiographical novel "The Strange Situation Witnessed in Twenty Years" written by the late Qing dynasty writer Wu Jianren, Chapter 80: "Besides, there is no precedent of joint marriage in the Manchu and Han dynasties. Where did this come from
Translation: And there is no precedent for the Manchu and Han ethnic groups to enter into marriage before, where did this statement come from.
2. Marriage: From the poem "To the Interior" by the famous Tang Dynasty writer and poet Bai Juyi, "I am also a loyal and hardworking scholar, and I am newly married to you
Translation: I am a steadfast and hardworking person who just married you.