Some contain data and pointers to related files. And some these application emails contain a bit of everything. AppleScript is an English-like language used to initiate and direct actions within or between applications. AppleScript sentences and statements are saved as scripts. These script files are read by the operating system, which converts the script's instructions into the Apple event messages it sends to the indicated applications, in order to accomplish the tasks the scripts were designed to address.
Some scripts contain instructions to an application.
Some are requests for information. Some send or refer to data for applications to process. Often, scripts perform all of these tasks. Scripts are composed using the Script Editor application. Every Macintosh comes with the Script Editor application installed.