The most important file in the data directory is the zotero.sqlite file, which is the database containing the majority of your data: item metadata, notes, tags, etc. When Zotero starts up, it reads the zotero.sqlite file in the active data directory.

Your data directory will likely contain several other files and folders. These can include zotero.sqlite.bak (an automatic backup of zotero.sqlite, which is updated periodically if the existing zotero.sqlite.bak file hasn't been updated in the last 12 hours) and zotero.sqlite.[number].bak files (automatic backups of zotero.sqlite that are created during certain Zotero updates), as well as folders such as locate, logs, pipes, styles, and translators that are created automatically at Zotero startup.




How Do I Backup My Zotero Library