The samples download provides over 100 samples for SQL Server 2005, demonstrating the following components:
The samples databases downloads include the AdventureWorks sample online transaction processing (OLTP) database, the AdventureWorksDW sample data warehouse, and the AdventureWorksAS sample projects which you can use to build the AdventureWorksAS BI database. These databases are used in the samples and in the code examples in the SQL Server 2005 Books Online. There is also a new sample database called AdventureWorksLT. This is a scaled-down sample database that those who are new to SQL Server will find easier to use and understand.
The text above is copied from MS Download Center.
Reference : Pinal Dave (http://blog.SQLAuthority.com)