None. The difference between "wedding rings" and "wedding rings" is pure and simple none. In the image above, both the letter A and the letter B rings can be called both. In each country, each language and each culture, the precious metal ring that symbolizes the union between the spouses can be called in different ways, such as "wedding ring", "wedding band" or combinations.

Custom dictates that the couple should give each other wedding rings as a symbol of the marriage alliance: he gives her one wedding band and she gives him another. He places his on her ring finger, and she on his ring finger... on the right or left hand depending on different cultural traditions: in Spain, for example, it is worn on the right hand, as in Germany, while in Catalonia and the former kingdoms of the Crown of Aragon it is carried in the left hand, as in France.

This rite was already practiced by the Romans before the introduction of Christianity, or by the Jews. "Non ornatus gratia, sed uí obsignaret qua domi erant": the Romans used it not as a mere ornament, but to give each other the power to seal letters or family possessions, since the ring was used as a practical seal of remove and put, as if it were a signature. Hence also the custom of the engagement ring as a promise of the future marriage alliance.

Both wedding rings and engagement rings are usually gold or silver, or bicolour, with or without diamonds or other precious stones, and their design largely depends on the taste of the bride and groom. They can be classic or vintage. Or with complementary designs. Or discreet. Or modern. Or originals...

To complicate it a little more, in jewelry jargon we speak of a "half alliance" when we refer to a ring with a diamond rail that covers half of the ring. And "alliance" when the diamond rail covers the entire circumference of the ring. But these terms are very technical in the field of jewelry.

In short: difference between "wedding rings" and "wedding rings"? None: they are exactly the same.