Wait, what? Where does it say we're an alternative to relational databases, or MySQL?

The whole article is a comparison to relational databases.

Nope, it's really not meant to be. But it is intended as a primer for those coming from a relational database background. CouchDB is NOT a replacement or an alternative to relational databases. CouchDB is fundamentally a different way to model data. That may work for you, it may not. CouchDB is not a panacea.

I think they're trying to say how they differ from relational databases since most people know and understand relational databases. It's like telling someone in America how cricket is played and using baseball as a base point to explain it.

Yes. Saying how something differs is called a comparison.

In response to "Wait, what? Where does it say we're an alternative to relational databases, or MySQL?" you responded: "The whole article is a comparison to relational databases."

Sure sounded to me like that was an answer to his question, and you were saying the author is saying CouchDB is an alternative to relational databases by saying it is a comparison.

I obviously wasn't trying to define what a comparison is, I was just giving a reason FOR this particular comparison.

You need not be so snide, sir.

The whole article is the first chapter of a book scheduled to be published in summer 2009. We are writing about the future here :)