About Report Builder and Report Manager
Report Builder is a small report design tool that is installed on your report server as part of Microsoft SQL Server. Similar in look and feel to Microsoft Word, it is a comfortable environment for users of other Microsoft Office tools. You can create simple or complex reports very quickly through wizards and an intuitive interface. If you have SQL and scripting skills you can customize SQL queries within Report Builder, but it is often just as quick to follow the UI and use the wizards.
Roles of Report Builder and Report Manager
Report Builder is where you have access to Templates and Report Parts provided by Report Manager (created from existing stock reports), tools to create custom reports varying from simple to complex and preview the reports.
Report Manager is where you upload the custom reports, configure UI controls, update an RDL, and ultimately, custom report users run the reports.
About Microsoft SQL Server and Report Builder Versions
SQL Server 2008 R2 supports Report Builder 3.0, which allows for creation of reusable and editable reports, including the creation and use of Report Parts.