SQLServerAgent is a Microsoft® Windows NT® service that executes jobs, monitors Microsoft SQL Server™, and fires alerts. SQLServerAgent is the service that allows you to automate some administrative tasks. As such, you must start the SQLServerAgent service before your local or multiserver administrative tasks can run automatically. SQL Server Agent is also supported on Windows® 95/98 platforms.
Note You can click SQL Server Agent in the console tree of SQL Server Enterprise Manager to administer jobs, operators, alerts, and the Windows NT service.
You can specify some configuration options for SQL Server Agent during SQL Server installation. The full set of configuration options is available from within SQL Server Enterprise Manager only.
Starting SQL Server Manually | How SQL Server Implements Security |