Wedding are celebrated differently by different peoplel; the rituals are quite different, even the clothes and stuffs but I think it always means- two people promising to be one forever.
So what is a wedding? I've read this article on Moissanite site about how the wedding evolved. Its history is pretty interesting. It tackles the time when man had to pay a price to marry the woman he loved, which is called "dowry". It also has some pretty interesting trivia about wedding, that I've never known prior to reading Moissanite site.
I guess everyone should really read this article, especially if you love weddings :)
I embedded the history of wedding from Moissanite below:

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