Desktop scripting/AppleScript

AppleScript

(Mac only)

"AppleScript is a scripting language created by Apple. It allows users to directly control scriptable Macintosh applications, as well as parts of macOS itself. You can create scripts—sets of written instructions—to automate repetitive tasks, combine features from multiple scriptable applications, and create complex workflows."

This is the easiest or most accessible way for a user to script something in OSX.

This is usually done in "Script Editor" or "Automator"

Personally, I've used AppleScript extensively to create "Docklets" to automate various tasks on OSX. Specifically, I toggle system settings, write files, and copy the active finder window's location to the clipboard.