Most of you have probably heard of the Business Data Catalog (BDC) that shipped with SharePoint 2007; it is a component that allows you to use external data inside of SharePoint. What you may not know is that in SharePoint 2010, the BDC got a new name: Business Connectivity Services (BCS). Microsoft changed more than just the name in 2010 though:
* While the BDC was only available to customers with the Enterprise license of SharePoint 2007, the BCS is available to all versions of SharePoint 2010, including SharePoint Foundation!
* The BDC only let you read data from your external systems but the BCS allows you to both read from and write data back to your external systems!
* The BDC allowed you to surface your external data in SharePoint but the BCS allows you to surface your external data in SharePoint AND inside of Office applications, meaning your data is that much more accessible!
* One of the big stumbling blocks in getting started with the BDC was the lack of tooling support from Microsoft. With the BCS both SharePoint Designer 2010 and Visual Studio 2010 have first-class support for building solutions with the BCS. What’s even better, many common scenarios can be handled with just SharePoint Designer 2010, without needing a developer or Visual Studio