The dtexec command prompt utility is used to configure and execute Microsoft SQL Server Integration Services (SSIS) packages.

The dtexec utility provides access to all the package configuration and execution features, such as connections, properties, variables, logging, and progress indicators.

The dtexec utility lets you load packages from three sources:

  1. Microsoft SQL Server databases
  2. The SSIS service
  3. The file system

MSDN has more details here: http://technet.microsoft.com/en-us/library/ms162810%28v=SQL.105%29.aspx