Recurrent Neural Networks. They&#x27;re so cool. Used in everything from creating chat bots to describing pictures to machine translation. Bengio and Goodfellow have a preprint book available <a href="https:&#x2F;&#x2F;goodfeli.github.io&#x2F;dlbook&#x2F;" rel="nofollow">https:&#x2F;&#x2F;goodfeli.github.io&#x2F;dlbook&#x2F;</a>