Reference:
Script Editor Toolbar and Tools Menu
Compiles the script into a form that can be run by the services. A compiled script is a file with the same name as the script, but a suffix of .DCF (Distribution Control File). Scripts are also compiled whenever you Run a Script or Schedule a Script for processing. Compiling also performs a syntax check on the script. Errors are flagged and reported on the status line. Only one error is reported each time you run the compiler.