The main differences between Drupal versions 7, 8, 9, and 10 are as follows:
1. Drupal 7: This version was released in 2011 and is known for its stability and extensive contributed module ecosystem. It uses the traditional procedural programming approach and has a user-friendly administrative interface. However, it lacks some modern features and architectural improvements.
2. Drupal 8: Released in 2015, Drupal 8 introduced significant changes compared to Drupal 7. It adopted a more modern object-oriented programming approach using Symfony components. It also introduced a new administrative interface, improved performance, and enhanced multilingual capabilities. Drupal 8 also emphasised a mobile-first approach and provided better support for responsive design.
3. Drupal 9: Released in 2020, Drupal 9 is an incremental update to Drupal 8. It removed deprecated code and updated dependencies to newer versions. Drupal 9 is backward-compatible with Drupal 8, making the upgrade process smoother. It also introduced new features and improvements, such as a new admin theme and enhanced media management.
4. Drupal 10: Drupal 10 was released in 2022. It continues the evolution of Drupal 9 by removing deprecated code and updating dependencies. Drupal 10 focuses on providing a smooth upgrade path from Drupal 9 and improving the developer experience. It also introduces new features and enhancements based on community feedback and requirements.
Each Drupal version brings new features, architectural improvements, and better performance compared to its predecessor. Upgrading to a newer version allows users to take advantage of these advancements and ensures ongoing support and security updates.