To export an entire library, right-click on it in the Zotero right pane and choose “Export Library…” (you can also find “Export Library…” in the “File” menu). To export an individual collection, right-click on it and choose “Export Collection…”. To export specific items, select them in the center Zotero pane, right-click, and choose “Export Items…”.

Please note: Import/export is not recommended for transferring entire Zotero libraries between systems, and, if you use Zotero's word processor plugins, links to Zotero items from existing word processor documents will be lost after an export/import.