Zotero's Groups feature allows you to share references with other Zotero users. It's a great way to work on collaborative research projects.
First, set up Zotero sync and synchronize your library.
You now have two sections in your Zotero collections pane: My Library and Group Libraries.
Personal and group libraries are entirely separate, so changes made to items in one library do not affect the other. You can drag items between libraries to copy items.
Search for existing public groups or create a new group. Groups may be public (searchable, and anyone can join) or private (users can only join if invited).