In this article I will describe what activity monitor is and how they are used.
An activity monitor for SQL Server is a utility for seeing the performance of your SQL Server. In other words, what the resources are used, what are the expensive queries, what memory and resources are taken etc.Now to see the Activity Monitor in SQL Server 2008.Step 1:First open the SQL Server 2008.Step 2:Right-click the SQL Server Engine and click "Activity Monitor". Step 3:After clicking that you will see like the following figure: See here you will see the 5 sections.
Basics of SQL Server