Once you have the Zotero desktop application downloaded to your computer, you can set up syncing by signing in using your Zotero username and password. Syncing allows you to access your Zotero library from any computer. Zotero provides you with 300 MB of free storage. You can purchase additional storage space on the Zotero website.
1. Click on Preferences under the Edit menu:
2. Click Sync and enter your Zotero username and password, and click Set Up Syncing:
3. Click on the "Sync with zotero.org" icon in the upper right-hand corner to sync your Zotero library: