Visual Studio Beta 2 Reporting Services RDLC files

As we all know, SQL Server Reporting Services reports are saved as .RDL files. The files saved and consumed by the VS/Beta 2 Web-based report designer and viewer control, however, are .RDLC files. So, what are the differences?

Thanks to Scott Allen, a fellow VSLive! presenter for providing these valuable links to RDLC files.