When a couple decides to live a household life together in marriage, then that's where a love symbol is needed. Generally, what is worn is jewelry in the form of rings. Why ring, because this one object has a deep meaning for binding a commitment named marriage.
Since the first ring is a valuable item that symbolizes immortality. When used for wedding symbols, the meaning becomes eternal togetherness that is timeless. In the past only important people and positions used rings. But now everyone can wear it regardless of their position.
The circular ring shape shows life like a spinning wheel. The ring that circles the partner's finger and your finger shows a strong commitment between a husband and wife to wade along the shared household ark.