no it is not a plugin, it is and extension that adds code to your php pages.
wordpress is a plugin that you add to your site pages, you can add both wordpress and eCart functionality to your pages if the pages are php.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.