BCS vs BDC in SharePoint :

BCS vs BDC in SharePoint :

BCS VS BDC IN SHAREPOINT :

Business Connectivity Services (BCS) :

• BCS is used to connect with external content like sql data.
• Using Business Connectivity Services, you can create, read, update, delete, and query (CRUDQ) to the external system from a Microsoft Office application or SharePoint site

Business Data Catalog

• It is the old version of the  BCS, it is also widely used to fetch external data.
• It differ from BCS by it can only read from external data,editing is not available here.

To see details about BCS see the link  Click here