WordPress is a free and open-source content management system (CMS) based on PHP and MySQL. Features include a plugin architecture and a template system. It is most associated with blogging but supports other types of web content including more traditional mailing lists and forums, media galleries, and online stores.
Magento is an eCommerce platform built on open source technology which provides online merchants with a flexible shopping cart system, as well as control over the look, content, and functionality of their online store. Magento offers powerful marketing, search engine optimization, and catalog-management tools.