, Files Connect is used to integrate Sharepoint Files/documents and Chatter i.e. you can browse through the documents in Site Collection/Sites/Sub-sites on Sharepoint from Salesforce Chatter itself, create a copy/reference of that file in Salesforce so that you can post it on Chatter/Records. You can also search Sharepoint files from Salesforce using Files Connect.

Salesforce Files Sync is another offering that helps to synchronize Salesforce Chatter Files (not Libraries yet) between Salesforce & PC.