A website is primarily for readable content. This is content but a site that is a single flash interactive movie is not. The movie itself is content but the web site contains one element and that is all.

That element when read by a blind user or a search engine is a very tiny amount of text. Hardly worth bothering about.

Once you understand this concept the answer to the question "what is a website" becomes much simpler to grasp.

But don't take my word for it.