Laravel facades serve as “static proxies“ to underlying classes in the service container, providing the benefit of a terse, expressive syntax while maintaining more testability and flexibility than traditional static methods. It’s perfectly fine if you don’t totally understand how facades work - just go with the flow and continue learning about Laravel.
If reading is more your style, first check out the Facade documentation. The Facade classes have a __callStatic which first checks for the container binding ID by calling static::getFacadeAccessor() (see #facade-class-reference) and then uses that to get the real underlying class from the DI Container.
Once that’s complete, then calls the actual method wanted (i.e. __callStatic arg) (see #L347).
Facade Documentation: