Objects gets more power over time.

obmodule.rb

class Person
   def say_hi
      puts "Hi, this is Ruby!"
   end
end

john = Person.new
robin = Person.new 

john.say_hi   # => Hi, this is Ruby!
robin.say_hi   # => Hi, this is Ruby!

module MyMethods
  def shout_hello
    puts "Hellloooo People"
  end
end

john.extend(MyMethods)

john.shout_hello   # => Hellloooo People
robin.shout_hello  # => NoMethodError: Undefined Method shout_hello 

od1.rb

class Person
   def say_hi
      puts "Hi, this is Ruby!"
   end
end

john = Person.new
robin = Person.new 

john.say_hi   # => Hi, this is Ruby!
robin.say_hi   # => Hi, this is Ruby!

def john.shout_hello
   puts "Hellloooo People"
end

john.shout_hello   # => Hellloooo People
robin.shout_hello  # => NoMethodError: Undefined Method shout_hello 

od2.rb

class Person
   def say_hi
      puts "Hi, this is Ruby!"
   end
end

john = Person.new
robin = Person.new 

john.say_hi   # => Hi, this is Ruby!
robin.say_hi   # => Hi, this is Ruby!

class Person
   def shout_hello
     puts "Hellloooo People"
   end
end 

john.shout_hello   # => Hellloooo People
robin.shout_hello  # => Hellloooo People