AFAIK

The Main Components of the SQL Architecture are NETWORK LIBRARY, provide connectivity between the client and the server process.(Client request come to  SQLserver via NL) DATABASE ENGINE, is the server process that sits at the heart if a SQL Server System(RDBMS). Its logically divided as Relational Engine and the Storage Engine. RELATIONAL ENGINE: RE provides the functionality that control query execution(the request is parsed, optimised and executed) OLE-DB Request is passed to the storage engine STORAGE ENGINE- SE pass the IO request to OS.(Storage Engine manages the access and modification of data. Transaction manager, Page Manager, Access methods, Lock manager, File/Device Manager, Buffer, log, sort manager and Utilities)

Named pipes enables clients applications to request a reliable and two way connection between the client application and Sql Server, across a network. A named pipe has a name which follows the UNC naming convention : \\Server\pipe\name The default names pipe for SQL server is :                 \\Server\pipe\sql\query A named instance would have a named pipe of                \\server\pipe\MSSQL$instancename\sql\query Early versions of SQL Server only provided Named Pipes. Named Pipes also allows for impersonation of a clients credentials. The feature is used by SQL server when using Linked Servers. The clients logon credentials are passed across to the Linked Server for authentication. Named Pipes can operate over TCP/IP, NETBEUI or IPX as it indirectly relies on the Common Internet Files Sytems