Apache has the ability to tune its returns to the abilities of the client—and even to improve the client's efforts. Currently, this affects:
The choice of MIME type returned. This is often used for images, which might be the very old-fashioned bitmap, the old-fashioned .gif, or the more modern and smaller .jpg. Apache's reactions can be extended and controlled with a number of directives.
The language of the returned file.
Updates to the returned file.
The spelling of the client's requests.