WordPress is an easy to use content management system (CMS). It’s broadly used on the internet to facilitate websites for organizations big and small. Additionally, it is well documented, along with a huge ecosystem of extensions to allow its use publishing personal weblogs to large consumer websites.
Drupal is a content management system (CMS) for websites. It is extensible, and at times overly complex. However, it does provide functionality not found in simpler CMS like WordPress.
There are two variations of Drupal, the more simplistic Drupal CMS, and the base Drupal Core for advanced use cases.