Getting Started with SQL Server 2008 R2 - Microsoft SQL Server 2008 R2 Administration - page 34

F Each column will have the same attributes as the column in the original table where
the attributes, such as data type and collation must be matched
How it works...
F The process of federated servers is implemented with the design architecture of the
User/Business/Data services tier.
F The initial tier of User Services is a set of thin clients that focus on managing the
application user interface.
F The User Services tier calls the next tier to perform the business functions needed to
support user requests.
F So the Business Services Tier consists of a set of 'COM+' components that
encapsulate the business logic of the organization. The Business Services tier uses
the next tier for any permanent data storage that has to be performed.
F The final stage of storage is the Data Services Tiers, such as SQL Server databases,
which can store data in a permanent medium. This is also referred to as persisting
the data.