dog.rb

class Dog 
  attr_reader :name, :age, :breed # etc
  def initialize(name, age, breed)
    @name = name
    @age = age
    @breed = breed
  end

  def name 
    @name 
  end 

  def speak
    puts "woof"
  end  
end 

tilly = Dog.new("tilly", 4, "border collie")
# => instance of a class
tilly.speak
# => instance method being called

# getters
p tilly.name
# => tilly