Enterprise Manager is the primary administrative tool for Microsoft SQL Server 2000 and provides a MMC

Microsoft Management Console

Microsoft Management Console is a component of Windows 2000 and its successors that provides system administrators and advanced users an interface for configuring and monitoring the system.- Snap-ins and consoles :...

–based user interface that allows users to:

• Define groups of servers running Microsoft SQL Server
  Microsoft SQL Server
  Microsoft SQL Server is a relational database server, developed by Microsoft: It is a software product whose primary function is to store and retrieve data as requested by other software applications, be it those on the same computer or those running on another computer across a network...
  
  .
• Register individual servers in a group.
• Configure all Microsoft SQL Server
  Microsoft SQL Server
  Microsoft SQL Server is a relational database server, developed by Microsoft: It is a software product whose primary function is to store and retrieve data as requested by other software applications, be it those on the same computer or those running on another computer across a network...
  
   options for each registered server.
• Create and administer all Microsoft SQL Server
  Microsoft SQL Server
  Microsoft SQL Server is a relational database server, developed by Microsoft: It is a software product whose primary function is to store and retrieve data as requested by other software applications, be it those on the same computer or those running on another computer across a network...
  
   databases, objects, logins, users, and permissions in each registered server.
• Define and execute all Microsoft SQL Server administrative tasks on each registered server.
• Design and test SQL statements, batches, and scripts interactively by invoking SQL Query Analyzer
  SQL Query Analyzer
  SQL Query Analyzer is a tool that allows graphic creation of queries and SQL scripts. It makes use of templates.Microsoft SQL Server 2000 SQL Query Analyzer is a graphical tool that allows you to:...
  
  .
• Invoke the various wizards defined for Microsoft SQL Server
  Microsoft SQL Server
  Microsoft SQL Server is a relational database server, developed by Microsoft: It is a software product whose primary function is to store and retrieve data as requested by other software applications, be it those on the same computer or those running on another computer across a network...
  
  .

MMC

Microsoft Management Console

Microsoft Management Console is a component of Windows 2000 and its successors that provides system administrators and advanced users an interface for configuring and monitoring the system.- Snap-ins and consoles :...

 is a tool that presents a common interface for managing different server applications in a Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 network. Server applications provide a component called an MMC snap-in that presents MMC users with a user interface for managing the server application. Microsoft SQL Server Enterprise Manager is the Microsoft SQL Server 2000 MMC snap-in.

In Microsoft SQL Server 2005, Enterprise Manager is replaced by SQL Server Management Studio

SQL Server Management Studio

SQL Server Management Studio is a tool included with Microsoft SQL Server 2005 and later versions for configuring, managing, and administering all components within Microsoft SQL Server...

, which provides a single interface to functionality provided by Enterprise Manager and Query Analyzer in Microsoft SQL Server 2000.

This entire statement is taken from the following Microsoft Website: http://msdn.microsoft.com/en-us/library/aa174466(v=sql.80).aspx