This state indicates a logical end of the process. Processes in this state are treated as completed.
For example, in a bug tracking request a valid end state is "Closed" which in case of an issue it could be "Resolved".
From the toolbar click Setup+Company
Under Workflow section, click on Manage Workflow Applications
Select an application
Select a process type. Click Workflow
Click Edit State, and under the Start State field select the End State.