Clear all registered TYPO3 caches, including opcode and dependency injection cache.
Compare and update the database table and field definitions of your installation against the specification defined for activated extension.
Clear temporary files including concatenated JS/CSS files and processed images.
Reset autoload information for active third party extensions.
Truncate persistent database tables which are not related to caching.
Verify the reference index for inconsistencies or rebuild it to update database relations.
Create new administrative users and grant them system maintainer privileges (optional).
Clear preferences and settings for all backend users. This action permanently deletes all user-specific data in the database table be_users.
Download and update language packs for installed extensions and the TYPO3 backend.