What does ::MyClass Ruby scope operator do?

This explicitly refers to the MyClass in the global scope. If there is a MyClass in the global scope, but also a MyClass inside of SomeModule, referring to MyClass from inside of SomeModule will refer to MyClass inside of the module, not the global MyClass. Saying ::MyClass explicitly refers to the MyClass in the global scope.

class MyClass def self.something puts "Global MyClass" end end module SomeModule class MyClass def self.something puts "SomeModule::MyClass" end end print "From the module: " MyClass.something print "Explicitly using global scope: " ::MyClass.something end print "From the global scope: " MyClass.something print "Explicitly using module scope: " SomeModule::MyClass.something