What Is ChatGPT Doing … and Why Does It Work?

(Stephen Wolfram)

Stephen Wolfram's Feb 2023 blog post is still cited as among the most technically-accurate-yet-beautifully-succinct write-ups of how the ChatGPT LLM works. There is a book out too.

https://writings.stephenwolfram.com/2023/02/what-is-chatgpt-doing-and-why-does-it-work/