It says its tailored for beginners, but I don't know what kind of beginner can parse multiple paragraphs like this:

"How wrong was the prediction? We need a single number that captures "the model thought the correct answer was unlikely." If the model assigns probability 0.9 to the correct next token, the loss is low (0.1). If it assigns probability 0.01, the loss is high (4.6). The formula is − log ⁡ ( � ) −log(p) where � p is the probability the model assigned to the correct token. This is called cross-entropy loss."