Python geoprocessing scripts can be executed either outside ArcGIS as standalone scripts or inside ArcGIS as script tools. Both methods have their advantages and disadvantages. Up to this point in the book, all our scripts have been run either inside ArcGIS as a script tool, from a Python development environment such as IDLE, or the Python window in ArcGIS. However, Python scripts can also be executed from the Windows operating system command line. The command line is a window that you can use to type in commands, rather than the usual point-and-click approach provided by Windows. This method of running Python scripts is useful for scheduling the execution of a script. There are a number of reasons why you might want to schedule your scripts. Many geoprocessing scripts take a long time to fully execute and need to be scheduled to run during nonworking hours on a regular basis. Additionally, some scripts need to be executed on a routine basis (every day, week, month, and so on), and should be scheduled for efficiency. In this chapter, you will learn how to execute scripts from the command line, place scripts inside a batch file, and schedule the execution of scripts at prescribed times. Keep in mind that any scripts run from the command line will still need access to an ArcGIS for Desktop license in order to use the arcpy module.