[cl42]

You're not wrong! After training, the neural network is in fact "hard coded" in that the weights do not change anymore.

During training, you update the weights. As a very, very simple example in relation to my original response above... Suppose you are training a neural network. You know that the probability of "weary" coming after "Once upon a midnight dreary, while I pondered, " is 1.00, right? So you set up your LLM with random weights, and you see that the probability estimate for "weary" is 0.77 (I'm making this # up)... Well you can now use an algorithm to nudge the neural network's weights in a way that makes the 0.77 closer to 1.00!

In other words -- the learning happens during training.

A good place to start might be this course: https://karpathy.ai/zero-to-hero.html

Depending on your sophistication and amount of free time you have, here are more resources: https://phaseai.com/resources/free-resources-ai-ml-2024

Good luck!