Your several stylesheets will be merged into a single compressed file, to optimize loading times for your users.
Rather than having several calls to several CSS, it is better for your visitors to have only one stylesheet. This speeds up load times, allows a more efficient cache management.
But for developing the CSS, it is often preferable to manage multiple specific files, specialized (one for reset, one for print version, another for small screens, etc..)
The purpose of this plugin is to allow you to work with various files, but merge them into one single file when the browser need it.
It can be generate each time (during development) or use a cache-file when finished.
It will optimize the CSS by removing all unnecessary characters that increase the CSS (tabs, spaces, line breaks ...).
All comments will be deleted - but you can insert a few lines at the top, to specify such a copyright ...