A profile is an xml file. This file, when installed on a device, configures the device to act in a certain way. Profiles began back in the iPhone Configuration Utility (the precursor to Apple Configurator) and have since moved to being the way you manage various settings on Apple operating systems like iOS, macOS, and tvOS.
When configuring iOS devices to use the settings you want, there’s generally three ways to go, manually configuring settings and profiles. For the Mac you have another option, scripting changes with defaults.
Manual configuration ...
