Backdrop CMS and Drupal are content management systems that are built on the same core principles and architecture of Drupal 7. They share a common heritage and were based on the same codebase, but they have evolved in slightly different directions and cater to different audiences.
They share features that make them distinct from other CMS for site builders that have structured data
Content types with web UI to add various fields
- Entity reference that allows site builders to connect easily connect and tag information stored in various content types via web UI
- Views module - visual query that allows power users to build complex index pages from existing content via web UI
- There three features made Drupal 7, which is foundation for both modern Drupal and BackdropCMS, preferred solution for ambitious site builders who needed to combine ease of use (like in Wordpress) with advanced features to build SQL queries without learning
Backdrop CMS can be seen as a sibling to Modern Drupal, addressing a specific segment of the user base, mostly site owners that do not have an IT team to support them. If you have an existing Drupal 7 site and are looking to upgrade it to a more modern version, you may consider moving to Backdrop CMS as it offers a smoother transition path. On the other hand, if you need to build a highly scalable enterprise-grade website, Drupal might be the more suitable choice.
Backdrop CMS is a fork of Drupal 7. It was created to provide an alternative for users who were accustomed to Drupal 7's architecture and concepts and were looking for a smoother upgrade path from Drupal 7 to a more modern codebase. Backdrop CMS aims to be user-friendly, more familiar to Drupal 7 users, and relatively easier to maintain.
Both Drupal and Backdrop CMS are part of the same ecosystem that is D7 heritage. Both contribute to the open-source community and share certain modules and themes. Drupal and Backdrop CMS ecosystem is continually evolving, and new updates or changes are happening as you read this post.