# Neural Networks and Transformers (Bonus Module)

Now that you have an overview, let's dive a bit deeper into this bonus module. This Bonus Module will be easier to understand if you're already familiar with Neural Networks, Backpropagation, Sequence-to-sequence learning, and libraries such as NumPy.

In the realm of machine learning, Transformers are akin to Optimus Prime in the Transformers movie series. Just as Optimus Prime can transform from a truck into a powerful leader, these models transform simple inputs into complex, insightful outputs, mastering tasks from language translation to code generation.

Transformers are central to revolutionary projects like AlphaFold 2 and NLP giants like GPT-4 and Llama. To truly grasp machine learning's potential, understanding Transformers is essential.

Today, we delve slightly into the core of these AI 'Optimus Primes'.&#x20;

<figure><img src="https://836496022-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FrUrbhS6sJTLDgZKE3ac6%2Fuploads%2F51JTice5unIE4kp9yWSo%2Fimage.png?alt=media&#x26;token=33c9bfb3-5f24-457f-a7ab-61f14762286c" alt="" width="375"><figcaption></figcaption></figure>

### First things first: Neural Networks and RNNs

Before we get into transformers, let's first understand the background. Let's start by getting a quick understanding of neural networks. Imagine them as the brains inside computers, designed to make sense of all sorts of information, whether it's a picture, a piece of music, or a sentence.

**Quick Look at Neural Networks**

* **What They Are:** Neural networks are like virtual brains in computers. They learn from examples and get really good at specific tasks.
* **How They Function:** They're made up of layers of 'neurons' that work together to understand and interpret data.

**Different Types for Different Tasks**

* **Convolutional Neural Networks (CNNs):**
  * **Role:** CNNs are like the eyes of the AI world, great for understanding images.
  * **How They Work:** They break down images into smaller pieces and learn to recognize patterns, sort of like how we piece together a puzzle.
  * **Uses:** They're behind the magic of facial recognition and reading handwritten notes.
* **Recurrent Neural Networks (RNNs):**
  * **Role:** RNNs are like the AI's language experts.
  * **How They Work:** They read sentences word by word, remembering each word as they go, much like reading a book.
  * **Challenges:** RNNs can get overwhelmed with really long texts, like long paragraphs, and sometimes forget the beginning by the time they reach the end. They also can be tough to train, with problems like forgetting earlier information (vanishing gradients) or learning too much all at once (exploding gradients).
  * **Uses:** They help in translating languages or powering chatbots.

Neural networks, like different tools in a toolkit, are specialized for specific kinds of jobs. CNNs excel with visuals, while RNNs handle language.&#x20;

But, as we'll see next, transformers brought new abilities to the AI world, especially in dealing with language more smartly.
