2.6. Content Negotiation

People from all over the world access the same Internet, using many different languages, many different character sets, and many different browsers. One representation of a document is not going to satisfy the requirements of all these people. This is why HTTP provides something called content negotiation, which allows clients and servers to negotiate the best possible format for each given resource.

For example, say you want to make a document available in multiple languages. You could store each translation of this document separately so that they each have a unique URL. This would be a bad idea for a number of reasons, but most importantly because you would have to advertise multiple URLs for the same resource. URLs have been designed to be easily exchanged offline as well as via hyperlinks, and there is no reason why people who speak different languages should not be able to share the same URL. By utilizing content negotiation, you can offer the appropriate translation of a requested document automatically.