WordPress is an open source blog tool and publishing platform powered by PHP and MySQL. WordPress started as just a blogging system, but has evolved to be used as a full Content Management System (CMS). It has many features including a plug-in architecture and a template system. It can be downloaded and installed free of cost from the official WordPress website.
WordPress is easy to learn. Users can re-arrange widgets without editing code. WordPress is very easy to implement in terms of SEO because it is designed to be search engine friendly and has built-in SEO benefits.