Whenever someone visits your site, even the search engines and yourself, the server has to send the files to them. This takes time and the larger the files are, the more time it takes. Many times, the files are large due to extra space in the files, sometimes doubleing their size. This package adds code that reduces the size of the files as they are loaded. An average reduction of 10 times for each page is typical and that is a tremendous savings in load time.
This package is not compatible with the Visual Verify contribution though it is with the more robust ReCaptcha system by google. If you are using the former and would like this installed, the Visual Verify code will need to be removed or changed to the ReCaptcha code.