class Foo
  def m1
    puts "private"
  end

  def m2
    puts "protected"
  end

  private :m1
  protected :m2

  def m3 #Private and Proteceted can be invoked indirectly like this thorough a function
    m1
    m2
  end

  def m4        #Protected can be invoked thorough a reciever
    m2
    self.m2
    Foo.new.m2
  end

  def m5  # Private cannot have reciever so self.m1 and Foo.new.m1 will throw error
    m1
  end
end