Classes in Ruby are a blue print for an object. Each time you call .new on a class a new instance of that class has been created. Creating and using classes allows you to create instances and share methods so that these all don't have to be defined each time. This is why each time you create an instance of an array class it has access to the array class methods. Say you want to create a class dog (and why wouldn't you?) to be able to set and get information about different dogs. Since class names are constant they will be capitalized. We will create a Dog class that takes the arguments of breed and age.

      class Dog
  
      def initialize(breed, age)
        @breed = breed
        @age = age
      end

      end
        
      

Ok so we have a class that doesn't do much. If we want to get information we will need to use a getter method or even better use a reader attribute. Reader attributes only retrieve information and do not change anything about it. Setter methods and writer attributes can change information (like age if the dog is now a year older). The accessor attribute can both read and write. Since a dog's breed won't change it only needs a reader method but it's age will change with time so it will need a reader and a writer, so an accessor.

      class Dog

      attr_reader :breed
      attr_accessor :age
  
      def initialize(breed, age)
        @breed = breed
        @age = age
      end

      def print_info
        puts "--New Dog --"
        puts "breed: #{:breed}"
        puts "age: #{:age}"
      end

      end
        
      

      charles_barkley = Dog.new("corgi", 7)
      charles_barkley.print_info
        returns -->
          --New Dog--
          breed: corgi
          age: 7