request and response

[sitaram irrinki]

Using requestdispatcher.include(request,response) we can include the
content generated by another servlet/html in the response.
The included servlet makes use of this request/response object pair.

But what is the use of this request/response pair if we are including an Html page(may be we generally don't include an Html page from a servlet but in case if we do so).
Is this just the syntax that we have to follow or is there any reason for this.