Ruby being an Object-Oriented language has the concept of self, but what is self? If you said, “It means current object”. You are right. But it is a bit more complicated than that. The keyword self in ruby gives access to the current object - the object that is receiving the current message. A method call in ruby is actually a message being sent to the receiver. When we write object.say_hello , we are sending the message say hello to the receiver object. object will respond to say_hello if there is a method body defined for it.

Inside the class self would mean the class itself, outside class self means main.

    class Person
      def i_am
        self    
      end
      
      def self.i_am
       self
      end
    end
 
    person = Person.new
    person.i_am  #=> #<Person:0x007fba740dc790>
    Person.i_am #=> Person
    self #=> main